Hey, size works against excellence.

When you revolutionize education, you're taking the very mechanism of how people be smarter and do new things, and you're priming the pump for so many incredible things.

There is a certain responsibility that accrued to me when I got to this unexpected position.

I have to admit that business-type thoughts do sneak into my head: I hope our customers pay us, I hope this stuff is decent, I hope we get it done on time. The little additions and subtractions that one has to do. Take sales, take costs and try to get that big positive number at the bottom.

Africa is on the rise.

If you've found some way to educate yourself about engineering, stocks, or whatever it is, good employers will have some type of exam or interview and see a sample of your work.

India just went 3 years with no cases [of polio]. Pakistan is our toughest location right now because some parts of the Taliban have not allowed vaccinators to come in and have even attacked vaccinators. We are hopeful this will get resolved since no one wants their kid to be paralyzed. I spend a lot of time making sure the polio campaign is doing the best it can. We have great computer models that help guide our activities.