Inactivity strikes us as intelligent behavior.

Long ago, Sir Isaac Newton gave us three laws of motion, which were the work of genius. But Sir Isaac's talents didn't extend to investing: He lost a bundle in the South Sea Bubble, explaining later, 'I can calculate the movement of the stars, but not the madness of men.' If he had not been traumatized by this loss, Sir Isaac might well have gone on to discover the Fourth Law of Motion: For investors as a whole, returns decrease as motion increases.

Of one thing be certain: if a CEO is enthused about a particularly foolish acquisition, both his internal staff and his outside advisors will come up with whatever projections are needed to justify his stance. Only in fairy tales are emperors told that they are naked.

Cash never makes us happy, but it's better to have the money burning a hole in Berkshire's pocket than resting comfortably in someone else's.

Chains of habit are too light to be felt until they are too heavy to be broken.

Investing in yourself is the best thing you can do. If you've got talents, no one can take them from you.

The commission of the investment sins listed above is not limited to 'the little guy.' Huge institutional investors, viewed as a group, have long underperformed the unsophisticated index-fund investor who simply sits tight for decades. A major reason has been fees: Many institutions pay substantial sums to consultants who, in turn, recommend high-fee managers. And that is a fool's game.