Actively seek out and listen carefully to negative feedback.

You want to do things you’re passionate about but also are useful to other people.

I'm extremely confident that solar will be at least a plurality of power, and most likely a majority... in less than 20 years.

The lessons of history would suggest that civilisations move in cycles. You can track that back quite far - the Babylonians, the Sumerians, followed by the Egyptians, the Romans, China. We're obviously in a very upward cycle right now and hopefully that remains the case. But it may not.

I think most of the important stuff on the Internet has been built. There will be continued innovation, for sure, but the great problems of the Internet have essentially been solved.

I don't think very highly of Henrik Fisker. [...H]e thinks the reason we don't have electric cars is for lack of styling

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.