The deepest theorems often have the simplest proofs - if you look at them from the right angle.
所有发生过一次的事物都不会再发生。但是所有发生过两次的事物必定会第三次发生。
The purpose of life is to live it, to taste experience to the utmost, to reach out eagerly and without fear for newer and richer experience.
数学是宇宙的语言，通过它，我们可以理解支配我们世界的基本原则。
They are not monuments, but footprints. A monument only says, 'At least I got this far,' while a footprint says, 'This is where I was when I moved again.'
