There is no man, however wise, who has not at some period of his youth said things, or lived in a way the consciousness of which is so unpleasant to him in later life that he would gladly, if he could, expunge it from his memory.

我明白了人生苦短，必须快乐。

成功的关键是坚持和永不放弃。

数学是一种超越文化和语言障碍的通用语言。