For David Gardner, the Rule Breaker Investing podcast isn't so much a monologue as it is an extended chat with you, his listeners and readers, which is one reason he ends every month with a mailbag episode -- so that he can bring your viewpoints and questions directly into the conversation.

In this segment, David offers an extended story arc from Eric, who has been a part of the Fool community for two decades. His investing life has had its ups and downs -- whose hasn't, if they've been in the market for any length of time? But both the good times and the bad have taught him things worth passing on to the next generation of Fool fans.

A full transcript follows the video.

This video was recorded on June 27, 2018.

David Gardner: Rule Breaker mailbag item No. 3, this is from Phil Kuni. Phil said, "I wrote you a note back in 2016 on LinkedIn while I was on a deployment with the Marine Corps that I thought you'd enjoy. I decided to send it again because I listen to you weekly on your Rule Breaker s podcast and know you enjoy getting notes from listeners and members."

Here was that note that Phil wrote back in 2016. "David, I wanted to send a sincere thanks to all at The Motley Fool who make investing fun, accessible and rewarding on behalf of a handful of Marines currently deployed to the Middle East. Listening to your podcasts and reading articles from fool.com have been a great way to take a mental break while working long hours in a high-stress environment. I've been sharing Foolish advice I've picked up with the Marines while we have down time. Most of them have limited investment experience and are just starting to think about where to put their hard-earned savings. The resources that The Motley Fool provides have been a catalyst for learning about investing and personal finance.

Some of them have opened brokerage accounts and have purchased their very first shares of individual stocks. It's been fun watching them get excited about investing and talk about owning a part of a business. It's even more encouraging that they have taken the first steps to building wealth over time by buying and holding good companies."

This next list of three companies that Phil called out two years ago among his fellow Marines makes me really happy. The next sentence said, " Tesla, Activision, and Netflix have been some of the most popular picks." This is my own insert, of course -- check out the returns of those companies as a small portfolio over the last two years.

Phil went on, "I wanted to share this with you and thank you for being an inspiration for a few Marines in the desert. We have four and a half months left before we head back to the States, and I'll do my best to keep them on track. Fool on! Your friend, Stock Advisor member, CAPS intern, and fellow Alexandrian, Phil Kuni."

Phil, it's great to hear from you again. In fact, I dropped Phil a note back and I said, "Hey, I think we'd all like to hear an update. How are things going since then?" Phil took the time to reply just a couple of weeks ago with this. "David, since my last note to you, the Marines and I safely returned from deployment back to Camp Pendleton, California.

Conversations about investing might seem out of place on a Marine Corps deployment to the Middle East, but on a nine-month deployment, there's not a lot you don't talk about. Additionally, many service members take advantage of the time apart from their daily lives back home to set personal goals for self-improvement, whether they be financial, fitness, or educational.

I'd also argue some of the qualities Marines are known for make them more predisposed to a Foolish investing philosophy. They have discipline and courage to withstand short-term market fluctuations. They have a knack for self-reflection and self-improvement and are eager to learn from their mistakes. Finally, they like keeping score, and don't like being short-changed if they could do better."

Phil concludes, "I left active duty last summer and I'm finishing my first year of an MBA program. I've been very fortunate to have both the opportunity to pursue lifelong financial education and the encouragement of people like my dad and The Motley Fool community to keep at it. Thanks again for all you do to make investing accessible and fun for ordinary people looking for extraordinary results, sometimes in extraordinary places. Semper Fool, Phil."

I think I'll leave that beautiful exchange right there.

As I mentioned, my friend Eric recently celebrated his 20th Fooliversary. He took the time to reflect back on those years of his life and the lessons that he learned about investing and himself over the course of that time. I think this is such a deeply beautiful note, and also one that packs so much insight that I insist -- and Eric has given me permission -- to share it here with you. So, let's get started. Settle in, Fools, here we go.

It starts this way. "Hello, Fools! Today is my 20th Fooliversary, for which I wanted to share my Foolish journey in 20 lessons learned from 20 years of Fool.

The Beginning. 20 years ago, a simple conversation proved to be a pivotal moment in my and my parent's lives, but we would not fully recognize its import for another 15 years. My colleague Sandra and I were chatting on that day of June 22nd, 1998, about some of the brand-new revolutionary web-based companies such as eBay and Amazon.

"Our conversation briefly skirted toward investing because I'd mentioned that my grandmother, who was then 93, had again gifted $10,000 of her Mobil stock to each of her heirs. She had purchased these shares back in the 1940s and 50s when she and my grandfather lived and worked in Colombia and Venezuela during the early days of the Gulf of Mexico and Caribbean Sea oil boom.

Sandra excitedly asked if I knew about The Motley Fool. Having never heard of it, she then spoke with enthusiasm that it teaches individual investors how to invest in the stock market. Intrigued, I looked into it. When I returned home, I signed up. Soon afterwards, I met David and Tom at the Bethesda, Maryland Barnes & Noble bookstore, which I believe has recently closed. Did you hear the teardrop fall?" Eric wrote. "After their fun and informative spiel, I waited in line to buy their book and had them sign it. I so enjoyed those guys and their goofy jester caps. I've enjoyed each time I've gotten to meet them since.

But now, the real beginning. Parents, please take notes. It actually began long before, as I've alluded to, because my grandparents on both sides of my family began investing in the 1940s. I watched my dad analyze companies and charts in our dining room when I was growing up. My parents and my mom's parents -- the ones in the oil business -- would talk around the family table about the businesses in which they owned stock. So, I was comfortable with business and the stock market.

Here come the early lessons. There are three of them. There's an obvious point here, with two more subtle ones. No. 1: I grew up around individuals owning stocks and holding onto them for their lifetime. No. 2: My family spoke more about the businesses they owned than of the movement of the stock prices, though the latter was always fun to follow. No. 3: Never once did they speak about selling their long-term, core holdings. The concept was simply absent."

Next section, entitled, "My First Tuition Payment: Black Monday, 19th October 1987. Oddly enough, even though I grew up with the stock market, I didn't have a clue how to invest with my corporate benefits after landing my first full-time job. Those were a mystery to me and seemed irrelevant at age 25. At the advice of an HR rep, I maximized my 401(k) savings and put it into a safe money market fund. He encouraged us new hires to revisit, after a few months, how we allocated the funds.

Unfortunately, I never thought about it again until six years later, when an also-young colleague implored me to move the funds into Peter Lynch's Magellan fund, showing me the data backing his own choice. I happily did so, unaware of the collision of that strategy with my goal of using the 401(k) to buy my first townhouse -- which, back then, you could do, penalty-free.

My time horizon was way too short to be in the stock market, but neither of us recognized that at the time. Six months later, Black Monday hit. We watched our 401(k)s fall 25% at the opening bell and slide another 25% over the next few months. Adding insult to injury, the IRS changed the rules, reinstating the customary 10% penalty for a first house, tuition or major medical.

I was so angry I could hardly sit still. There goes my house, up in flames! Yet, instead of bailing out of the stock market at those horrible lows, I chose instead to win by hanging in there. That's what my family always had done through many recessions, so I was confident it would recover in time, as it always had. Lo and behold, my 401(k) fully recovered 12 months later, helped along by my continued contributions throughout the storm. Best of all, these contributions made a killing that year.

Lessons from Black Monday. Here are three more lessons that emerged from the ashes of Black Monday." Again, we're working toward 20 lessons, so here we go. "No. 4: I held all of my 401(k) mutual fund during that ferocious decline, which made 2008 and 2009 feel like a leisurely stroll downhill. No. 5: I kept adding to my 401(k) Magellan fund position as the market collapsed and recovered, making my best returns by far with those contributions. No. 6: I learned about time horizons. Keep any funds you will need within the next three to five years out of the stock market and in cash or its equivalent."

The next chapter, entitled, "My Second Tuition Payment -- .boom to .bust, 2001. The stock market was booming with .com enthusiasm by the time I discovered The Motley Fool. I soon became fully invested, and like everyone else, began making impressive gains -- so impressive that I quit my day job in August 2000 to put full time into analyzing companies and posting what I learned on The Fool's discussion boards.

Of particular interest me was answering the question of why failed small-caps had failed. The answer was and remains debt. They're not big enough to withstand a shock to their finances when they carry debt. The Motley Fool liked my analysis of Foolish Eight Small Caps enough to invite me to become a plank holder of their new Soapbox service, where Fools like me could publish our reports for sale.

Like so many, I was convinced that the internet revolution would sweepingly change business and society. That belief sustained our acceptance of the absurdly high stock market valuations. I was so confident, in fact, that I went on margin, despite the warnings of The Fool itself. It was a heady time, and we all know it ended very poorly for nearly everyone, including Fool HQ. Many were laid off, Soapbox was closed up, and my finances were obliterated.

While we were correct in our belief of the internet revolution, we were disastrously wrong about the timeline and in who would capture the value created. We believed the transformation would be completed within three years, when the reality was more like ten years, and it's still under way. More crushingly, however, was our belief that shareholders would capture most of the value. The reality is that customers captured most of it, and they continue to do so to this day. That's not so bad, really, as every one of us is an internet customer.

".bomb lessons," Eric wrote, "these may have been my hardest-earned lessons at all." Here we go, No. 7-12. "No. 7: Keep your day job, as you may simply be lucky, not smart, and luck runs out. No. 8: Keep all your contacts from your day job if you do quit, as you may need them again one day. Fortunately, I was good about this one. No. 9: Understand the hype cycle. Euphoria is the worst time to buy, while despair is the best time to buy. No. 10: Learn how to value hyper-growth companies. Forget earnings and EBITDA. Focus on sales, operating cash flow, and the ever-intangible visionary leadership. No. 11: Ask, who will capture the value created by a novel technology? If it's not the companies you're invested in -- perhaps it's the customer -- then you will lose money. No. 12: Don't use margin. That was the leverage that ultimately crushed me. Let me repeat that: don't use margin."

The next chapter, "Applying the Education -- Boldly Stepping Forth in 2008." Eric goes on, "For two years, I was out of the workforce, during which I worked on a book with a best friend, never published but invaluable to us, and helped out a failing start-up. It failed, but gave me invaluable insights and lessons in start-ups.

When the last of the money ran out, I went back to work on my mom's birthday in October 2003 -- best birthday present ever, yes? -- to rebuild my finances and help another best friend, who was a single mom with a daughter heading off to college and a son in high school. Except for my new 401(k), I stayed out of the stock market as I again began saving for the down payment on a house.

Five years later, in 2008, the bottom once again fell out of the stock market, but this time, I was prepared. By November 2008, the economy and market had gotten so bleak that I took it as a sign from above to forget about my house and go all-in to the stock market, using Rule Breaker s, Stock Advisor, and Hidden Gems as my initial guides.

For the next four and a half years, I lived frugally and shoved every dime I could into the stock market. I joined Duke Street -- now Motley Fool ONE -- and explored every service they had until, after several years, I understood the strategy that suited my own temperament and life situation. I now buy companies with superior business economics, visionary leadership, strong and preferably multiple growth opportunities, and disciplined risk management, then hold them for years, if not forever, as my grandparents did. By following The Motley Fool's extraordinary strategy and education, my first Amazon position -- bought 18th November 2008 -- is a 44-bagger. My first Netflix position -- bought 18th May 2009 -- is a 75-bagger."

Here come lessons No. 13-17. "This is what I wish I had been doing from the outset -- lessons for the long journey. No. 13: Live frugally. Do you really need all the stuff? A simpler life helps you discover and focus on what's truly important to you. No. 14: Invest the savings. It's so much fun reading about what to buy next and then buying it. Knowing I was successfully attaining my financial goals gave me a sense of growing independence and freedom. No. 15: The Motley Fool's philosophy of buying quality companies with bright futures and holding them for the long-term through even difficult volatility has proven itself, over the past 15 years, in so many Foolish portfolios. No. 16: Discover your own strategy and adapt it to meet your current circumstance as you migrate through life's phases. No. 17: Market declines are buying opportunities. Welcome them. It is so much fun watching your returns skyrocket over the years as the market recovers and recommences its ascent."

Now to early retirement and more Motley Fool time. Eric went on, "By the time I was laid off in May 2013 at age 57, I was both eligible for early retirement and financially in a position to do so, as long as I continued living somewhat frugally. I wasn't penny-pinching, but I was doing things like driving a now-20-year-old car, so I could do more interesting things, such as travel to Alaska, snowshoe Mount Hood in Oregon, visit family and friends around the country, and finally, buying that house near Portland, Oregon.

After retiring, I again became more actively involved in The Fool community. The Motley Fool later picked a bunch of us for their new Farm Team. I began as a ticker guide for GoPro, unfortunately not one of my better stock picks," as has been often talked about on this podcast, "then slowly added coverage for several other companies. Many Motley Fool ONE members have thoroughly enjoyed attending The Fool member conferences at HQ and around the country. The presentations have been invaluable. Meeting so many Fools, employees and members alike, is a true highlight, as everyone becomes a real, tangible person.

Investment lesson No. 18: Getting involved with The Motley Fool community really ups your own investment game, and it makes your Motley Fool experience so much more fun and engaging. Start with a simple introduction or question on the discussion boards. I lurked for four months before asking a very basic question. It's deadly snowballed from there. The hardest part is making that first post, but it gets so much easier after that, and the rewards, both financial and social, are immense.

My parents win, too. One of the most satisfying aspects of my journey with The Motley Fool is that I introduced Daddy to The Motley Fool. He, too, liked what he saw, began diversifying his and Momma's investments using Income Investor, greatly boosting their dividend yield while reducing their nearly exclusive exposure to the oil and gas industry. That was a most fortuitous shift, as the oil and gas industry nosedived a few years later in 2015. The transformation of their portfolio has wonderfully transformed their retirement years.

Lesson No. 19: Sharing is at the heart of Fooldom. Share your knowledge of investing with family and friends and encourage them to check out fool.com. It just might change their lives, as David and Tom changed our lives by reaching out to all of us Fools. There is no need to proselytize, simply let others know about your involvement with The Motley Fool when appropriate. If you see interest, gently encourage it. People often ask me what I've been doing since retirement. Well, let me tell you about my experiences with The Motley Fool ...

Finally, lesson No. 20, the 20th lesson for 20 years: Be grateful for your health and the opportunities it gives you for your prosperity, and the opportunities it gives you, and most of all, for those who love you and the meaning they give to your life. Then give it all forward, wrapped in kindness. My very best to all, Foolish Eric."

That was probably the longest read that I may ever perform on this podcast. In many ways, it expresses a journey that many of us have been on. Eric, like a lot of us, has lived through those last 20 years. Just think about the drama that any of us could have had going through 2000-2001, then 2008-2009, and then the tremendous run that the stock market has made in periods that weren't within those bear market years. The good news is, most of them have been bull market years.

I love the candid nature of Eric's expression, the mistakes that he's made. Each of those 20 lessons could be shared with a friend or family member. I took a lot away from that, as well, Eric.

As Dylan mentioned earlier in this podcast, it is The Motley Fool's 25th anniversary this month. I'm going to put that forward as a contribution toward honoring the 25 years of The Motley Fool -- in this case, through the eyes of one investor. But, I think for a lot of us, as longtime Fools, people who may have discovered the website 25 years ago, 20, ten, five years ago, we can relate to what Eric's saying. He helps us think aspirationally about what we'd like to become.

So, I want to thank Eric for that wonderful note, and for the kindness and patience for all of you listening.

John Mackey, CEO of Whole Foods Market, an Amazon subsidiary, is a member of The Motley Fool's board of directors. David Gardner owns shares of ATVI, AMZN, NFLX, and TSLA. The Motley Fool owns shares of and recommends ATVI, AMZN, GPRO, NFLX, and TSLA. The Motley Fool recommends eBay. The Motley Fool has a disclosure policy.