In this segment of the Rule Breakers podcast,  Motley Fool co-founder David Gardner digs into the mailbag and combines his response to a pair of somewhat parallel notes: one from a dad helping his daughter pick her first investments, and one from an investor who's noticing an interesting trend about where (or rather, when) her winningest picks seem to come from.

A transcript follows the video.

This podcast was recorded on Sept. 28, 2016.

David Gardner: OK. Mailbag item No. 2 this month. I'm just going to put two together. These are kind of fun. We need to be quick on this anyway this month, so the first one comes from a longtime Fool I know from our Motley Fool community, Paul Hooper. He's @Selzhanik on Twitter.

He wrote: "On CAPS just two months, my daughter points out her best stock is the one she picked entirely herself." And the second one, kind of connected with this, but from a completely different person. This is from Celeste Ireland, @CelesteIreland on Twitter, and she wrote: "Sorted my scorecard by purchase date and found the further back I go, the less losers I have. Great lesson to #BuyandHold."

And the reason I put these both together is because I really appreciate positive expressions of what's working for you. And what we have, here, is we have a dear father working with his daughter to get her picking her first stock, and then a woman who has taken the time to look backward and recognize that scoring herself, as she's doing using a scorecard (which is just great), you're seeing that sure enough, if you let these stocks ... If you kind of leave your portfolio alone and don't be overactive, especially selling too quickly, you'll find that what looked like a dog, maybe that first year or two, can turn around and all of a sudden become a winner for you.

It's funny that I'm noting... Let's just talk about a stock like Exelixis. The ticker symbol is EXEL. It's a biotech company aimed at cancer solutions. I'm noticing it because this week it crossed the 100% gain mark. Now, that's the good news. The bad news is I picked it, along with my team, in 2005 for Motley Fool Rule Breakers. So here we are, 11 years later, and we just crossed a double. The stock market has exceeded that. The stock market's up about 140% over the same period.

ButExelixis has gone up literally 93.5% in the last three months, so most of the gains you had to wait 11 years to get. And where Exelixis is, now, with its cancer solutions and the stage of the company, still not a profitable company, but I think it could be one or two pops away from being a stock that ends up being a long-term winner. Now this isn't a big stock for us at Motley Fool Rule Breakers, but it's a great example of how if you let enough time pass, and you have good people doing good work, and you're invested in their business, you can sometimes turn a lemon into (sorry for the cliché) lemonade.