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

终点总是比你想象的更近。

In mathematics, the most profound ideas often arise from the simplest observations.

暮春三月,穿上春天的衣服,约上五六人,带上六七个童子,在沂水边沐浴,在高坡上吹风,一路唱着歌而回