Mankind invented a system to cope with the fact that we are so intrinsically lousy at manipulating numbers. It's called the graph.

Another thing I think should be avoided is extremely intense ideology because it cabbages up one's mind. You see it a lot with T.V. preachers (many have minds made of cabbage) but it can also happen with political ideology. When you're young it's easy to drift into loyalties and when you announce that you're a loyal member and you start shouting the orthodox ideology out, what you're doing is pounding it in, pounding it in, and you're gradually ruining your mind. So you want to be very, very careful of this ideology. It's a big danger.

In business we often find that the winning system goes almost ridiculously far in maximizing and or minimizing one or a few variables - like the discount warehouses of Costco.

You don't have to have perfect wisdom to get very rich - just a bit better than average over a long period of time.

Over many decades, our usual practice is that if something we like goes down, we buy more and more. Sometimes something happens, you realize you’re wrong, and you get out. But if you develop correct confidence in your judgment, buy more and take advantage of stock prices.

You're looking for a mispriced gamble. That's what investing is. And you have to know enough to know whether the gamble is mispriced. That's value investing.

Is anyone really surprised that Warren, who is the ultimate embodiment of concentrated decision-making power, picked somebody [Bill and Melinda Gates] who he thinks is like him in many important ways? It was a noble and sensible decision.