Wesco had a market capitalization of $40 million when we bought it [in the early 1970s]. It's $2 billion now. It's been a long slog to a perfectly respectable outcome - not as good as Berkshire Hathaway or Microsoft, but there's always someone in life who's done better.

It's a rare business that doesn't have a way worse future than it has a past.

The idea of excessive diversification is madness. Wide diversification, which necessarily includes investment in mediocre businesses, only guarantees ordinary results.

You want to deliver to the world what you would buy if you were on the other end.

We believe that almost all really good investment records will involve relatively little diversification. The basic idea that it was hard to find good investments and that you wanted to be in good investments, and therefore, you'd just find a few of them that you knew a lot about and concentrate on those seemed to me such an obviously good idea. And indeed, it's proven to be an obviously good idea. Yet 98% of the investing world doesn't follow it. That's been good for us.

This is an amazingly sound place. We are more disaster-resistant than most other places. We haven't pushed it as hard as other people would have pushed it. I don't want to go back to Go. I've been to Go. A lot of our shareholders have a majority of their net worth in Berkshire, and they don't want to go back to Go either.

You must force yourself to consider opposing arguments. Especially when they challenge your best loved ideas.