I don't invest in what I don't understand. And I don't want to understand Facebook.

Understanding how to be a good investor makes you a better business manager and vice versa.

I see almost no change in the price of the composite product that flows through Costco I don't feel sorry for the people who pay $27 million for an 8,000-square-foot condo in Manhattan. So inflation comes in places.

...in terms of business mistakes that I've seen over a long lifetime, I would say that trying to minimize taxes too much is one of the great standard causes of really dumb mistakes. I see terrible mistakes from people being overly motivated by tax considerations. Warren and I personally don't drill oil wells. We pay our taxes. And we've done pretty well, so far. Anytime somebody offers you a tax shelter from here on in life, my advice would be don't buy it.

The harder you work, the more confidence you get. But you may be working hard on something that is false.

You've got to have models in your head and you've got to array you experience - both vicarious and direct - onto this latticework of mental models.

It would be easier to screw up American Express than Coke or Gillette, but it's an immensely strong business.