We all are learning, modifying, or destroying ideas all the time. Rapid destruction of your ideas when the time is right is one of the most valuable qualities you can acquire. You must force yourself to consider arguments on the other side.

I've heard that one-half of the students at elite schools want to go into private equity or hedge funds. They want to keep up with their age cohorts at Goldman. This can't possibly end well in terms of meeting these expectations.

Capitalism is a pretty brutal place.

It is remarkable how much long-term advantage people like us have gotten by trying to be consistently not stupid, instead of trying to be very intelligent.

Mimicking the herd invites regression to the mean.

I have concluded that most PhD economists under appraise the power of the common-stock-based "wealth effect," under current extreme conditions... "Wealth effects" involve mathematical puzzles that are not nearly so well worked out as physics theories and never can be... What has happened in Japan over roughly the last ten years has shaken up academic economics, as it obviously should, creating strong worries about recession from "wealth effects" in reverse.

You've got to have models in your head and you've got to array you experience - both vicarious and direct - onto this latticework of mental models.