Acknowledging what you don't know is the dawning of wisdom.

We have a higher percentage of the intelligentsia engaged in buying and selling pieces of paper and promoting trading activity than in any past era. A lot of what I see now reminds me of Sodomand Gomorrah. You get activity feeding on itself, envy and imitation. It has happened in the past that there came bad consequences.

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.

Our experience tends to confirm a long-held notion that being prepared, on a few occasions in a lifetime, to act promptly in scale, in doing some simple and logical thing, will often dramatically improve the financial results of that lifetime.

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.

I would argue that a majority of the horrors we face would not have happened if the accounting profession developed and enforced better accounting.

In my whole life, I have known no wise people (over a broad subject matter area) who didn't read all the time - none, zero. You'd be amazed at how much Warren reads - at how much I read. My children laugh at me. They think I'm a book with a couple of legs sticking out.