Beta and modern portfolio theory and the like - none of it makes any sense to me.

The Berkshire-style investors tend to be less diversified than other people. The academics have done a terrible disservice to intelligent investors by glorifying the idea of diversification. Because I just think the whole concept is literally almost insane. It emphasizes feeling good about not having your investment results depart very much from average investment results. But why would you get on the bandwagon like that if somebody didn't make you with a whip and a gun?

An investment decision in the common stock of a company frequently involves a whole lot of factors interacting ... the one thing that causes the most trouble is when you combine a bunch of these together, you get this lollapalooza effect.

If you can buy the best companies, over time the pricing takes care of itself.

You have to have a temperament to grab ideas and do sensible things. Most people don’t grab the right ideas or don’t know what to do with them.

[With] closet indexing....you're paying a manager a fortune and he has 85% of his assets invested parallel to the indexes. If you have such a system, you're being played for a sucker.

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.