Don't do cocaine. Don't race trains. And avoid AIDS situations.

Go to bed smarter than when you woke up.

You must have the confidence to override people with more credentials than you whose cognition is impaired by incentive-caused bias or some similar psychological force that is obviously present. But there are also cases where you have to recognize that you have no wisdom to add - and that your best course is to trust some expert.

This is a good life lesson: getting the right people into your system is the most important thing you can do.

It is an unfortunate fact that great and foolish excess can come into prices of common stocks in the aggregate. They are valued partly like bonds, based on roughly rational projections of use value in producing future cash. But they are also valued partly like Rembrandt paintings, purchased mostly because their prices have gone up, so far.

Economists get very uncomfortable when you talk about virtue and vice. It doesn't lend itself to a lot of columns with numbers. But I would argue that there are big virtue effects in economics. I would say that the spreading of double-entry bookkeeping by the Monk, Fra Luce de Pacioli, was a big virtue effect in economics. It made business more controllable, and it made it more honest.

Stock-picking is like gambling: those who win well, seldom bet, but when they do, they bet heavily.