The ideas of economists and political philosophers， both when they are right and when they are wrong， are more powerful than is commonly understood. Indeed the world is ruled by little else. Practical men， who believe themselves to be quite exempt from any intellectual influence， are usually the slaves of some defunct economist.

做你自己，因为别人已经有人做了。

我不会让过去定义我的未来。

Mathematics is not just about numbers, equations, computations, or algorithms: it is about understanding.

最好的艺术留给你的问题比答案更多。