I was announcing to the public, in 2006, that I'd be leaving Microsoft in a couple of years and focusing full-time on the foundation. That was the time at which we went back to New York and Warren [Buffett] announced these gifts to a number of foundations, with a very high percentage of it going to us and basically doubling our capacity.

As we have taken diarrhea and pneumonia down, even malaria down quite a bit, the portion of the days that are very early in that 5 years - the first month, the first day - it's about half now. Yet that's the part we understand the least.

When you say that after World War I there was a pandemic that killed more people than the war itself, most will say: "Wait, are you kidding? I know World War I, but there was no World War 1.5, was there?" But people were traveling around after the war, and that meant the force of infection was much higher. And the problem is that the rate of travel back then was dramatically less than what we have nowadays.

In order for the United States to do the right things for the long term, it appears to be helpful for us to have the prospect of humiliation. Sputnik helped us fund good science - really good science: the semiconductor came out of it.

I don't think you're as capable of handling lack of sleep or whatever challenges you throw at your body as you get older. However, I never missed a day of work.

Every three years, we have to go to the governments and say, okay, you know you're saving millions of lives and even though your budgets are tight, helping Africa avoid this disaster really is a priority.

I can understand wanting to have millions of dollars; there's a certain freedom, meaningful freedom, that comes with that.