Because of inertia or just a failure to pay attention to my financial affairs, I left the money in the money market fund for the next 5½ years until I retired. During those years, the money market fund earned a paltry average of 4.6 percent a year, while the Windsor Fund turned in an annualized gain of 18 percent a year.

Naturally, my wife and friends wanted to know how a financial writer who was knowledgeable about the markets could make that kind of mistake. I don't have a good answer. But I did learn a valuable lesson: Don't try to outguess the market. Decide on your long-term investment strategy, and as long as it's the right strategy for you, stick to it.