精神错乱：一遍又一遍地重复作同一件事，而期待会有不同的结果。

Mathematics is a way of thinking, not just a collection of facts.

"A good programmer is not one who knows all the answers, but one who knows how to find them."

Geometry is knowledge of the eternally existent.

"To write is to struggle and to resist; to write is to become; to write is to draw a map of the world that has not yet been explored."

最重要的是保持真实。