There is always something to worry about. Avoid weekend thinking and ignoring the latest dire predictions of the newscasters. Sell a stock because the company's fundamentals deteriorate, not because the sky is falling.

In this business if you're good, you're right six times out of ten. You're never going to be right nine times out of ten.

You get recessions, you have stock market declines. If you don't understand that's going to happen, then you're not ready, you won't do well in the markets.

There's no use diversifying into unknown companies just for the sake of diversity. A foolish diversity is the hobgoblin of small investors. That said, it isn't safe to own just one stock, because in spite of your best efforts, the one you choose might be the victim of unforeseen circumstances. In small portfolios, I'd be comfortable owning between three and ten stocks.

Well, I think the secret is if you have a lot of stocks, some will do mediocre, some will do okay, and if one of two of 'em go up big time, you produce a fabulous result. And I think that's the promise to some people.

A stock market decline is as routine as a January blizzard in Colorado. If you're prepared, it can't hurt you. A decline is a great opportunity to pick up the bargains left behind by investors who are fleeing the storm in panic.

The list of qualities (an investor should have) include patience, self-reliance, common sense, a tolerance for pain, open-mindedness, detachment, persistence, humility, flexibility, a willingness to do independent research, an equal willingness to admit mistakes, and the ability to ignore general panic.