Elon Musk: “When I launched SpaceX, one of my closest friends made me watch a compilation of rocket chess. A lot of people tried to dissuade me. The punchline was: how do you make a fortune in the rocket business? You start with a big fortune.

I’d heard that joke so many times that I would recite the punchline myself. People would ask me: ‘Why did you start a rocket company?’ and I’d say that I was trying to find the fastest way to turn a large fortune into a small one.

But I already knew that the probability of failure was high and the chance of success low. I thought SpaceX might have a 10 to 20% chance of succeeding.”