Expectations are a form of first-class truth: If people believe it, it's true.

I think philanthropy is also growing and catching on. Figuring out how the philanthropy sector, which is quite small compared to the private sector, which is the biggest by far, and then the governments, you know, even in these poor countries over time has to take on these key responsibilities. How does philanthropy accelerate that? Drive the kind of innovations, make sure they get used well. So it plays this kind of special role.

Know your numbers' is a fundamental precept of business.

When I was in college, for the games of that era, I was as hard core as anyone was. I wouldn't say I outgrew it, but you always have to have a finite number of addictions.

We have two other countries, Pakistan and Afghanistan - again it's the instability that is a problem there. So over the next several years, we expect to drive the number of [polio] cases back down to zero because that is likely to be the second disease after smallpox that we completely eradicate.

Now we've got that [children's death rate] down to about 5 percent, so we've more than cut it in half, and that's because we're getting vaccines out, economic improvement also helps there, but the vaccines are why we've seen an acceleration in getting that down.

In fact, that's where my vision of the coming digital opportunity is somewhat different from other people's. I divide it into three parts. One is the office. That's the one I'm most excited about and is the most concrete.