If you're trying to create a company, it's like baking a cake. You have to have all the ingredients in the right proportion.

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?'

The thing that's worth doing is trying to improve our understanding of the world and gain a better appreciation of the universe and not to worry too much about there being no meaning. And, you know, try and enjoy yourself. Because, actually, life's pretty good. It really is.

We have a strict 'no a-hole policy' at SpaceX. And we fire people they are. I mean, we give them a little bit of warning. But if they continue to be an a-hole, then they're fired.

Many things are improbable, only a few are impossible.

You need to live in a dome initially but over time you could terraform Mars to look like Earth and eventually walk around outside without anything on. ... So it's a fixer-upper of a planet.

There's nothing - I've bought everything I want. I don't like yachts or anything; you know, I'm not a yacht person, and I've got pretty much the nicest plane I'd want to have.