I think the idea that the hedge fund manager gets lower taxes than the taxi driver or the physics professor is insane. The legislators who leave that policy in place are derelict in their duties to be rational and fair. There are plenty of them in both political parties. It's totally outrageous.

We're guessing at our future opportunity cost. Warrenis guessing that he'll have the opportunity to put capital out at high rates of return, so he's not willing to put it out at less than 10% now. But if we knew interest rates would stay at 1%, we'd change. Our hurdles reflect our estimate of future opportunity costs.

A foreign correspondent, after talking to me for a while, once said: "You don't seem smart enough to be so good at what you're doing. Do you have an explanation?"

Berkshireis not as good as it was in terms of percentage compounding [going forward], but it's still a hell of a business.

It's my guess that something like 5% of GDP goes to money management and itsattendant friction. I define it broadly - annuities, incentive pay, all trading, etc. Nobody else has used figures that high, but that's my guess. Worst of all, the people doing this are among the best and the brightest. Hundreds and thousands of engineers, etc. are going into hedge funds and investment banking. That is not an intelligent allocation of the brainpower of the civilization.

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.

A lot of opportunities in life tend to last a short while, due to some temporary inefficiency... For each of us, really good investment opportunities aren't going to come along too often and won't last too long, so you've got to be ready to act and have a prepared mind.