The idea that we will make a society where literally everybody is graded, the good at the top, bad at the bottom, exactly done as it should be, is impossible. There are simply too many random factors: accidents, accidents of birth, accidents of things dropping on people's heads, illnesses, etc. We will never get to grade them, never get to grade people as they should.

A proof is a way to convince yourself and others that something is true.

过度捕捞只会让海洋资源枯竭，我们必须走绿色渔业之路。

The study of mathematics is a constant dialogue between the concrete and the abstract.