Polio's pretty special because once you get an eradication, you no longer have to spend money on it; it's just there as a gift for the rest of time.

If you say to people that there's less violence today than in the past, they would be stunned to hear that. But it's the truth, even though we have awful things happening in Syria or Sudan.

Headlines, in a way, are what mislead you because bad news is a headline, and gradual improvement is not.

I appoint the laziest person to do the hardest job as they'll find the easiest way to do it

I have a particular relationship with Vinod Khosla because he's got a lot of very interesting science-based energy startups.

The world is progressing and resources are becoming more abundant. I'd rather go into a grocery store today than a king's banquet a hundred years ago.

Long-term vision and product strategy.