It's very useful to have a good grasp of all the big ideas in hard and soft science. A, it gives perspective. B, it gives a way for you to organize and file away experience in your head, so to speak.

I’d say that Berkshire Hathaway’s system is adapting to the nature of the investment problem as it really is. We’ve really made the money out of high quality businesses. In some cases, we bought the whole business. And in some cases, we just bought a big block of stock. But when you analyze what happened, the big money’s been made in the high quality businesses. And most of the other people who’ve made a lot of money have done so in high quality businesses.

Berkshire's whole record has been achieved without paying one ounce of attention to the efficient market theory in its hard form. And not one ounce of attention to the descendants of that idea, which came out of academic economics and went into corporate finance and morphed into such obscenities as the capital asset pricing model, which we also paid no attention to. I think you'd have to believe in the tooth fairy to believe that you could easily outperform the market by seven-percentage points per annum just by investing in high volatility stocks.

A board member should be perfectly willing to leave at any time and willing to make the tough calls.

We believe that almost all really good investment records will involve relatively little diversification. The basic idea that it was hard to find good investments and that you wanted to be in good investments, and therefore, you'd just find a few of them that you knew a lot about and concentrate on those seemed to me such an obviously good idea. And indeed, it's proven to be an obviously good idea. Yet 98% of the investing world doesn't follow it. That's been good for us.

If (investing) weren't a little difficult, everybody would be rich.

Forgetting your mistakes is a terrible error if you are trying to improve your cognition.