The possibility that stock value in aggregate can become irrationally high is contrary to the hard-form "efficient market" theory that many of you once learned as gospel from your mistaken professors of yore. Your mistaken professors were too much influenced by "rational man" models of human behavior from economics and too little by "foolish man" models from psychology and real-world experience.

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

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.

Trying to prioritize among things we're unlikely to do is pretty fruitless.

At Berkshire Hathaway we do not like to compete against Chinese manufacturers.

I knew a guy who had $5 million and owned his house free and clear. But he wanted to make a bit more money to support his spending, so at the peak of the internet bubble he was selling puts on internet stocks. He lost all of his money and his house and now works in a restaurant. It's not a smart thing for the country to legalize gambling [in the stock market] and make it very accessible.

It would be nice if this [finding really cheap stocks] happened all the time. Unfortunately, it doesn't.