Wrigley is a great business, but that doesn't solve the problem. Buying great businesses at advantageous prices is very tough.

I get flack for saying [when I visit a college and give a speech], "This is a nice college, but the really great educator is McDonald's." They hate me for saying this and think I'm a slimy creature. But McDonald's hires people with bad work habits, trains them, and teaches them to come to work on time and have good work habits. I think a lot of what goes on there is better than at Harvard.

We have the same problem as everyone else: It's very hard to predict the future.

I know just enough about thermodynamics to understand that if it takes too much fossil-fuel energy to create ethanol, that's a very stupid way to solve an energy problem.

I have a name for people who went to the extreme efficient market theory-which is "bonkers". It was an intellectually consistent theory that enabled them to do pretty mathematics. So I understand its seductiveness to people with large mathematical gifts. It just had a difficulty in that the fundamental assumption did not tie properly to reality.

Fixable but unfixed bad performance is bad character and tends to create more of itself, causing more damage to the excuse giver with each tolerated instance.

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