Starting and growing a business is as much about the innovation, drive and determination of the people who do it as it is about the product they sell.

The revolutionary breakthrough will come with rockets that are fully and rapidly reusable. We will never conquer Mars unless we do that. It'll be too expensive. The American colonies would never have been pioneered if the ships that crossed the ocean hadn't been reusable.

What most people know but don't realize they know is that the world is almost entirely solar-powered already. If the sun wasn't there, we'd be a frozen ice ball at three degrees Kelvin, and the sun powers the entire system of precipitation. The whole ecosystem is solar-powered.

I’m nauseatingly pro-American. I would have come here from any country. The U.S. is where great things are possible.

You have to be pretty driven to make it happen. Otherwise, you will just make yourself miserable.

Going from PayPal, I thought: 'Well, what are some of the other problems that are likely to most affect the future of humanity?' Not from the perspective, 'What's the best way to make money?'

Fear is a hard thing to deal with. I feel it quite strongly. If I think something is important enough, I'll make myself do it in spite of fear. But it can really sap the will. I hate fear, I wish I had it less.