In ninth grade, I came up with a new form of rebellion. I hadn't been getting good grades, but I decided to get all A's without taking a book home. I didn't go to math class, because I knew enough and had read ahead, and I placed within the top 10 people in the nation on an aptitude exam.

Scientists and companies weren't creating things like new vaccines. Now that we have this fund that's there to buy at the lowest price, but buy for those people these medicines, we see scientists everywhere coming up with those new tools.

Microsoft is not about greed. It's about innovation and fairness.

Two out of every five people on Earth today owe their lives to the higher crop outputs that fertilizer has made possible.

Don't wallow in failure. Instead, learn from it.

Hopefully, whether it's energy or child vaccines, the case of the many benefits helping countries so that they are stable, so these refugee problems that have been troubling for Europe - a little less so for the U.S. but, even so, a lot of controversy there - these things are why the future's going to be better than the past. People really do look to the United States, so we'll be there making the case.

Teaching's hard! You need different skills: positive reinforcement, keeping students from getting bored, commanding their attention in a certain way.