"You can't go back and change the beginning, but you can start where you are and change the ending."
你无法回到过去改变开头，但可以从现在开始改变结局。
The mathematician's best work is art, a high perfect art, as daring as the most secret dreams of imagination, clear and limpid.
每一个词都是通向理解的一步，每一句话都是通向另一个灵魂的桥梁。