Missing out on some opportunity never bothers us. What's wrong with someone getting a little richer than you? It's crazy to worry about this.

When you borrow a man's car, always return it with a tank of gas.

A lot of people with high IQs are terrible investors because they've got terrible temperaments. And that is why we say that having a certain kind of temperament is more important than brains. You need to keep raw irrational emotion under control. You need patience and discipline and an ability to take losses and adversity without going crazy. You need an ability to not be driven crazy by extreme success

Rationality is not just something you do so that you can make more money, it is a binding principle. Rationality is a really good idea. You must avoid the nonsense that is conventional in one's own time. It requires developing systems of thought that improve your batting average over time.

It's stupid the way people extrapolate the past -- and not slightly stupid, but massively stupid.

You must force yourself to consider opposing arguments. Especially when they challenge your best loved ideas.

...all man's desired geometric progressions, if a high rate of growth is chosen, at last come to grief on a finite earth. And the social system for man on earth is fair enough, eventually, that almost all massive cheating ends in disgrace.