生活就像一首歌，有高潮也有低谷，但其中总有美好。

In mathematics, the journey is just as important as the destination.

The true teacher defends his pupils against his own personal influence. He inspires self-distrust. He guides their eyes from himself to the spirit that quickens him. He will have no disciple.

Mathematics is not a careful march down a well-cleared highway, but a journey into a strange wilderness, where the explorers often get lost.

释义：做事要有合理的理论依据，这样有利于成就大事。自古以来，征战与讨伐必须师出有名。