If it is wisdom you're after, you're going to spend a lot of time on your ass reading.

Choose clients as you would friends.

[In picking stocks] You really have to know a lot about business. You have to know a lot about competitive advantage. You have to know a lot about the maintainability of competitive advantage. You have to have a mind that quantifies things in terms of value. And you have to be able to compare those values with other values available in the stock market.

Of course I'm troubled by huge consumer debt levels - we've pushed consumer credit very hard in the US. Eventually, if it keeps growing, it will stop growing. As Herb Stein said, "If something cannot go on forever, it will stop." When it stops, it may be unpleasant. Other than Herb Stein's quote, I have no comment. But the things that trouble you are troubling me.

Black-Scholes works for short-term options, but if it's a long-term option and you think you know something [about the underlying asset], it's insane to use Black-Scholes.

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.

Bernie Ebbers and Ken Lay were caricatures - they were easy to spot. They were almost psychopaths. But it's much harder to spot problems at companies like Royal Dutch [Shell].