I could go insane if I obsessed over every little detail of all of my companies. My management philosophy is to pay attention to the vital few and ignore the trivial many.

When you start with next to nothing, all you've got is a lot of thought, a lot of innovation, figuring new ways to do things without using a lot of money.

I like to live well and I feel good about it because I know how much we give back. There's plenty for my family, now let's take care of the rest.

At least once a year, I meet with a group called the Giving Pledge. It's a group of billionaires - including me, Warren Buffett, Bill Gates, and Ted Turner - who have pledged to give away most of their money to charity. We meet for three days to talk about what we're doing to help make the planet a better place to live.