Almost everything worthwhile carries with it some sort of risk, whether it's starting a new business, whether it's leaving home, whether it's getting married, or whether it's flying in space.

Sweat the small stuff. Without letting anyone see you sweat.

It’s not enough to shelve your own competitive streak. You have to try, consciously, to help others succeed.

There's really just one thing I can control: my attitude during the journey, which is what keeps me feeling steady and stable, and what keeps me headed in the right direction. So I consciously monitor and correct, if necessary, because losing attitude would be far worse than not achieving my goal.

Anticipating problems and figuring out how to solve them is actually the opposite of worrying: it's productive.

I want to know: How does a space suit on Mars work? Show me how it is pressurized, and how it is cooled. What's the glove design? None of that stuff can be bought off the rack. It does not exist. You can't just go to SpaceMart and buy those things.

If you haven't learned to ride a bike by the time your peer group has, then suddenly it's an embarrassment and you'll avoid opportunities where you're expected to ride a bike. And then it starts shaping your behaviour. Reading is much subtler, but much more destructive if you have not - for whatever reason - learned to read by the time you should.