I like people admitting they were complete stupid horses' asses. I know I'll perform better if I rub my nose in my mistakes. This is a wonderful trick to learn.

When it gets into these spikes, with shortages and uproar and so forth, people go bananas, but that's capitalism.

People like the robber barons assumed that the doctrine of the survival of the fittest authenticated them as deserving power. You know, "I'm the richest. Therefore, I'm the best. God's in his heaven, etc." And that reaction of the robber barons was so irritating to people that it made it unfashionable to think of an economy as an ecosystem. But the truth is that it is a lot like an ecosystem. And you get many of the same results.

Understanding both the power of compound interest and the difficulty of getting it is the heart and soul of understanding a lot of things.

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

In fact I've probably never seen such a wide moat.

Obviously, consideration of costs is key, including opportunity costs. Of course capital isn't free. It's easy to figure out your cost of borrowing, but theorists went bonkers on the cost of equity capital. They say that if you're generating a 100% return on capital, then you shouldn't invest in something that generates an 80% return on capital. It's crazy.