The purpose of abstraction is not to be vague, but to create a new semantic level in which one can be absolutely precise.

You never know what worse luck your bad luck has saved you from.

每个故事都是谎言，直到有人相信它。

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

Drawing for children is about capturing the essence, not the detail.

每次失败都会受伤。但你必须重新站起来继续前进。