The early personal computers were not very powerful so the idea of feeding their program into a small amount of memory requires immense skill.

Computers and games don't waste time - people do.

If your goal is to make the world a better place, one thing you can do is pick a specific challenge that you really care about. Then, learn as much as you can about it and try to volunteer your time to help an organization that is working in this area. While you're doing that, look for creative new ways to use technology to tackle parts of the problem that you come in contact with.

Looking at these issues as a businessman, I believe that investing in the world's poorest people is the smartest way that our government spends money.

The US in some ways has been the best. Who figured out shale gas? Although that wasn't a good thing [for CO2 levels], it was very innovative. It's led to low-cost energy. Who figured out nuclear power? Largely the United States. Once you get past the steam engine, which is mostly British, then the US has been at the center of most of the energy things that have happened.

When you program, you want to think you're writing the best possible program for the... for the task you're trying to solve.

(On being the world's richest man) I wish I wasn't ... There's nothing good that comes out of that. You get more visibility as a result of it.