Finding a single investment that will return 20% per year for 40 years tends to happen only in dreamland. In the real world, you uncover an opportunity, and then you compare other opportunities with that. And you only invest in the most attractive opportunities. That's your opportunity cost. That's what you learn in freshman economics. The game hasn't changed at all. That's why Modern Portfolio Theory is so asinine.

We like our current shareholders and don't want to entice anyone to become one. It would help current shareholders to hear our CEOs [of the Berkshireoperating subsidiaries], but we promised them they could spend 100% of their time on their business. We place no impediments on them running their businesses. Many have expressed to me how happy they are that they don't have to spend 25% of time on activities they didn't like.

You don't want to be like the motion picture exec who had so many people at his funeral, but they were there just make sure he was dead. Or how about the guy who, at his funeral, the priest said, "Won't anyone stand up and say anything nice for the deceased?" and finally someone said, "Well, his brother was worse."

The idea of caring is that someone is making money faster [than you are] is one of the deadly sins. Envy is a really stupid sin because it’s the only one you could never possibly have any fun at. There’s a lot of pain and no fun. Why would you want to get on that trolley?

The general systems of money management [today] require people to pretend to do something they can't do and like something they don't. It's a terrible way to spend your life, but it's very well paid.

Black-Scholes is a know-nothing system. If you know nothing about value - only price - then Black-Scholes is a pretty good guess at what a 90-day option might be worth. But the minute you get into longer periods of time, it's crazy to get into Black-Scholes. For example, at Costco we issued stock options with strike prices of $30 and $60, and Black-Scholes valued the $60 ones higher. This is insane.

A different set of incentives from rising in an economic establishment where the rewards system, again, the reinforcement, comes from being a truffle hound. That's what Jacob Viner, the great economist called it: the truffle hound - an animal so bred and trained for one narrow purpose that he wasn't much good at anything else, and that is the reward system in a lot of academic departments.