有喜怒哀乐之情却没有发作，这是从凡人之心直接追溯到道德之心，使人们存心修养；虽未发生但却有喜怒哀乐的表现，这是由道心指出人心的缺欠，要人们反省改正。

I am too intelligent, too demanding, and too resourceful for anyone to be able to take charge of me entirely. No one knows me or loves me completely. I have only myself.

The only way to get to the top is to climb the mountain, not to wait for the elevator.

The most important thing in mathematics is to ask the right questions.