I've always been amazed by Da Vinci, because he worked out science on his own. He would work by drawing things and writing down his ideas. Of course, he designed all sorts of flying machines way before you could actually build something like that.

Your most unhappy customers are your greatest source of learning.

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.

We need to cooperate globally on epidemic preparedness and prevention in the same way we are cooperating globally to stop people from getting nuclear weapons.

There are no significant bugs in our released software that any significant number of users want fixed.

You will NOT make $60,000 a year right out of high school. You won't be a vice-president with a car phone until you earn both.

This antitrust thing will blow over.