Life is about making an impact, not making an income.

The beauty of the world has two edges, one of laughter, one of anguish, cutting the heart asunder.

The essence of mathematics is not to make simple things complicated, but to make complicated things simple.

The only limit is the one you set yourself.

不把别人所不懂的告诉别人，把别人知道的东西告诉别人。