生活是世界上最罕见的事情，大多数人只是存在，仅此而已。
To live is the rarest thing in the world. Most people exist, that is all.
Never stop learning. The moment you think you know it all is the moment you fail.
I have already carried out my duty. I have proved the Poincaré conjecture and I have nothing more to do in mathematics.
我不是来完美的，我是来勇敢的。