Mathematicians grow very old; it is a healthy profession. The reason you live long is that you have pleasant thoughts. Math and physics are very pleasant things to do.

Mathematics is a vast adventure; its history reflects some of the noblest thoughts of countless generations.

I've lived this long because I didn't die.

To her surprise, Lucky tilted his head and looked her in the eye, appearing oddly…crestfallen, she thought. “Don’t be nervous, ” he said. “I hate making you nervous.

We must be careful what we imagine, fear, or hope for. The echoes of our thought live on in eternity.

Who are we to think we deserve anything? What makes us so great? No one is "lucky" to have us. We are all full of it.

I started writing stories in sixth grade. But writing wasn't cool, like being good at sports, or being part of the in crowd, or winning fights on the playground.

You now have permission to be strong and healthy and calm and relaxed. There's no place else to go. There's nothing else to do.

No one knows how to make going to orbit orders of magnitude safer and orders of magnitude more affordable.

My weapon is just a movie.

Do what you want to do, and don't worry if it's a little odd or doesn't fit the market.

I do not allow myself vain regrets or foreboding.

Laughter is the language of the soul.