"A few things have worked out very well [for me]. And the nice thing about the investment business is that you don't need very many. You'll see plenty of times when you get chances to do things that just shout at you. And the thing you have to do is, when that happens, you have to take a big swing. That is no time to be reading a book on the theory of diversification....When you find something where you know the business is within your circle of competence, you understand it, the price is right, the people are right--then you take your thumb out of your mouth and you barrel in."