It's hard to predict what will happen with two brands in a market. Sometimes they will behave in a gentlemanly way, and sometimes they'll pound each other. I know of no way to predict whether they'll compete moderately or to the death. If you could figure it out, you could make a lot of money.

If you don't allow for self-serving bias in the conduct of others, you are, again, a fool.

Proper accounting is like engineering. You need a margin of safety. Thank God we don't design bridges and airplanes the way we do accounting.

After nearly making a terrible mistake not buying See's, we've made this mistake many times. We are apparently slow learners. These opportunity costs don't show up on financial statements, but have cost us many billions.

If you want to understand science, you have to understand math. In business, if you're enumerate, you're going to be a klutz. The good thing about business is that you don't have to know any higher math.

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.

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