It can take some people a long time to get the message and change their ways.

Consider, for instance, of some mutual fund managers, such as those at the American Heritage Growth (FUND:AHEGX) fund. The fund racked up double-digit yearly losses five times from 2001 through 2007. It has lost a whopping 95% of its value over the past decade, with a 90% drop just since 2005. You'd think that along the way, the managers might have decided they needed to drastically alter their ways -- and perhaps simply exit the business. (If you're curious, as I was, the fund's top holdings recently included Intel (NASDAQ:INTC), Citigroup (NYSE:C), and Hythiam (NASDAQ:HYTM).)

Then there's Bonnie Ashley. She's an 11-time divorcee. Yes, that's right. She's formed and dissolved 11 unions over 32 years. According to an article in the Delaware News Journal, the longest marriage was two years, and the shortest just 45 days. There have "only" been seven men involved in these 11 marriages -- she married two of them three times.

As I read about her story, I was struck by some investing lessons embedded in it.

Daddy dearest
For starters, she points to a disappointing relationship with her father as one driver of her trouble finding Mr. Right. Many of us also, often without being too conscious of it, behave in less than perfect ways, because of early influences in our lives. For example, those who grew up in the Depression or were otherwise deprived can become hoarders in life. Those who lived through a major stock market crash often swear off stocks entirely and never realize or accept that ups and downs are inevitable in the market.

It's not just the overall market that's volatile -- even solid, dependable stocks can exhibit a jumpy pattern. Look at IBM (NYSE:IBM) over the years. In split-adjusted terms, it was trading around $30 per share in 1990, only to drop to $10 by 1993. By 1999, it was back up to nearly $140. It dipped back down to $60 in 2002 and ended that year in the $80s. And here we are again, back to almost $130 again, as I write this. Over the past 20 years, though, all of those ups and downs translate to a simple 9.5% average annual gain.

Misguided persistence
Then there's Bonnie Ashley's attitude: "I told my mom that I would marry 27 times [before] I got it right." Yikes.

I admire her hopefulness and optimism in the face of her track record. But after a few divorces, I'd think she might want to re-evaluate her approach and outlook.

The same goes for stocks. With investments, we're often hesitant to let go. We might tell ourselves we won't sell a poorly performing stock because it pays dividends, for example. Well, you can invest in some great and growing companies that also pay dividends, so why not seek out both dividends and stock-price appreciation?

Never again

Ashley now swears that she'll never marry again. But she's missing the point. It's not that marriage is a bad idea. She's just been going about it poorly. As she admits, she often married a guy before she'd taken the time to get to truly know him. That approach can derail our stock investing, too. Years ago, I invested in companies I hardly understood, often with poor results. Sun Microsystems (NASDAQ:JAVA), KLA-Tencor (NASDAQ:KLAC), and even Oracle (NASDAQ:ORCL) ... could I tell you exactly how they made their money and how strong their competitive positions were? Not a chance.

Be smart
So let's go ahead and invest for the long haul, but only after we learn a lot about the companies we buy. As Fool co-founder David Gardner has explained, buying good companies early and holding them for the long term is "the greatest secret of all."

For monthly recommendations of promising dividend payers, I invite you to test-drive, for free, our Motley Fool Income Investor newsletter service. Last time I checked, it sported more than 20 recommendations with dividend yields topping 6%!

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