When people discover they are no good at baseball or hockey, they put away their bats and their skates and they take up amateur golf or stamp collecting or gardening. But when people discover they are no good at picking stocks, they are likely to continue to do it anyway.

The S&P is up 343.8 percent for 10 years. That is a four-bagger. The general equity funds are up 283 percent. So it's getting worse, the deterioration by professionals is getting worse. The public would be better off in an index fund.

The Rule of 72 is useful in determining how fast money will grow. Take the annual return from any investment, expressed as a percentage, and divide it into 72. The result is the number of years it will take to double your money.

That's not to say there's no such thing as an overvalued market, but there's no point worrying about it.

All the time and effort people devote to picking the right fund, the hot hand, the great manager have, in most cases, led to no advantage.

Never invest in anything that cannot be illustrated with a crayon

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.