I try to get rid of people who always confidently answer questions about which they don't have any real knowledge.

Even bright people are going to have limited, really valuable insights in a very competitive world when they're fighting against other very bright, hardworking people. And it makes sense to load up on the very few good insights you have instead of pretending to know everything about everything at all times.

Economics is in many respects the queen of the soft sciences. It's expected to be better than the rest. It's my view that economics is better at the multi-disciplinary stuff than the rest of the soft science. And it's also my view that it's still lousy.

A lot of opportunities in life tend to last a short while, due to some temporary inefficiency... For each of us, really good investment opportunities aren't going to come along too often and won't last too long, so you've got to be ready to act and have a prepared mind.

You have to have a temperament to grab ideas and do sensible things. Most people don’t grab the right ideas or don’t know what to do with them.

Wrigley is a great business, but that doesn't solve the problem. Buying great businesses at advantageous prices is very tough.

Finding a single investment that will return 20% per year for 40 years tends to happen only in dreamland. In the real world, you uncover an opportunity, and then you compare other opportunities with that. And you only invest in the most attractive opportunities. That's your opportunity cost. That's what you learn in freshman economics. The game hasn't changed at all. That's why Modern Portfolio Theory is so asinine.