The first chance you have to avoid a loss from a foolish loan is by refusing to make it; there is no second chance.

The basic concept of value to a private owner and being motivated when you're buying and selling securities by reference to intrinsic value instead of price momentum - I don't think that will ever be outdated.

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.

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

I think we have some special talents. That being said, I think it's dangerous to rely on special talents - it's better to own lots of monopolistic businesses with unregulated prices. But that's not the world today. We have made money exercising our talents and will continue to do so.

The world is getting very much more competitive.

Opportunity cost is a huge filter in life. If you've got two suitors who are really eager to have you and one is way the hell better than the other, you do not have to spend much time with the other. And that's the way we filter out buying opportunities.