People are building the software and so having the pieces be such that a single person understands all the tradeoffs and everything that's going on in a piece is extremely valuable. It avoids getting into an experimental mode where you're just trying things out. That never works.

Investing in innovation, which was my broad theme talking to [Warren Buffett ], that included health vaccines, it included energy and education.

The quality of research in the U.S. is absolutely the best.

We got a malaria initiative, really a phenomenal time, even though in the early stages there was some uncertainty. Then of course [Barack] Obama, although he had budget constraints, he believed in these things; a lot of new initiatives, including in agriculture.

All lives have equal value. And so you say, 'why do poor children die when other children don't? Why do some people have enough nutrition or reasonable toilets and other people don't?' So those basic needs that, through innovation, actually it's very affordable to bring them...to everyone.

I remember in 1980 or 1981 looking at a list of people who had made a lot of money in the computer industry and thinking, Wow, that's amazing. But I never thought I'd be on that list. It's clear I was wrong. I'm on the list, at least temporarily.

One thing I've always loved about the culture at Microsoft is there is nobody who is tougher on us, in terms of what we need to learn and do better, than the people in the company itself. You can walk down these halls, and they'll tell you, 'We need to do usability better, push this or that frontier.'