All of a sudden people in the United States start to realize that vaccines make a difference. The controversy and the myth that's there, we're always trying to bust through that. So when I see a disease outbreak, I say to myself, "OK, that'll get people realizing how lucky we are to have vaccines."

What great changes have not been ambitious?

When girls are educated and free to pursue their passions, they contribute more to a thriving society. When women have a voice, they raise it to demand a life that is greater than what they've been told they have a right to expect. And these demands change the future for everyone.

Microsoft certainly makes products for the Macintosh.

It is still just unbelievable to us that diarrhea is one of the leading causes of child deaths in the world.

Our desire to bring every good thing to our children is a force for good throughout the world. It’s what propels societies forward.

Everyone agrees that the failure of our high schools is tragic. It's bad business, and it's bad policy. But we act as if it can't be helped. It can be helped. We designed these high schools; we can redesign them.