As you heat the planet up, it's just like boiling a pot.

Entrepreneurship is like eating glass and walking on hot coals at the same time

You want to be extra rigorous about making the best possible thing you can. Find everything that's wrong with it and fix it.

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?'

Some companies out there quote a start of production that is substantially in advance of when customers get their cars.

For my part, I will never give up, and I mean never.

Boeing just took $20 billion and 10 years to improve the efficiency of their planes by 10 percent. That's pretty lame. I have a design in mind for a vertical liftoff supersonic jet that would be a really big improvement.