How do you compete against a true fanatic? You can only try to build the best possible moat and continuously attempt to widen it.

Determine value apart from price; progress apart from activity; wealth apart from size.

...being an effective teacher is a high calling.

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.

It's simplicity itself that its future will be way worse than its past.

One of the first big bubbles, of course, was the huge and horrible South Sea Bubble in England. And the aftermath was interesting. Many of you probably don't remember what happened after the South Sea Bubble, which caused an enormous financial contraction, and a lot of pain. They banned publicly traded stock in England for decades.

I talked to one accountant, a very nice fellow who I would have been glad to have his family marry into mine. He said, "What these other accounting firms have done is very unethical. The [tax avoidance scheme] works best if it's not found out [by the IRS], so we only give it to our best clients, not the rest, so it's unlikely to be discovered. So my firm is better than the others." [Laughter] I'm not kidding. And he was a perfectly nice man. People just follow the crowd...Their mind just drifts off in a ghastly way.