The world is before you and you need not take it or leave it as it was when you came in.

认识你自己。

Mathematics is not a spectator sport. You have to get involved.

"You can’t just sit down and write a book. That’s not how books get written. Books get written by living your life, by being open to the world, by paying attention."

人依靠自己的力量人才能生存,不依靠自己的力量人就不能生存。