Jumping to conclusions. We all create hypotheses in undisciplined fashion, and then you have to go back and be intellectually disciplined.

Ironically, though, this is also the purchase in which I made my biggest mistake - of a kind, however, never recognized on financial statements. We paid $600 million in 1989 for Gillette preferred shares that were convertible into 48 million (split-adjusted) common shares. Taking an alternative route with the $600 million, I probably could have purchased 60 million shares of common from the company. The market on the common was then about $10.50, and given that this would have been a huge private placement carrying important restrictions, I probably could have bought the stock at a discount of at least 5%. I can't be sure about this, but it's likely that Gillette's management would have been just as happy to have Berkshire opt for common. But I was far too clever to do that.

Checking email when I don’t know an answer.

My worst intellectual habit has to be overanalyzing everything. I do it all the time, because there are too many options in this world.

Well, I'll be honest with you. I was a theoretical physicist but my Ph.D. work was on a problem that was not particularly interesting to me at the time. And I used to subscribe to Scientific American and I found that there were all these wonderful discoveries happening in biology and I also knew that a number of physicists had gone into biology and been successful. So, I decided to switch.

No, because I started working on ribosomes when I was a post doc, in 1978, when it would have been impossible, really, to solve it. But, it was just a fundamental problem in biology. And we felt, no matter, anything we do to chip away at the problem would be useful. So it was more that that attracted me. And I think the fact that it was large and kind of difficult to come to grips with, yes, it was attractive. Really what was attractive was that it was a fundamental problem.