学习某事的最好方法就是去教它。
The relation between what we see and what we know is never settled.
翻译：真正的朋友，顺境时不添虚假繁华，逆境时不改变初心，富贵时不忘记旧交，这样的情谊才珍贵。
"I am free, no matter what rules surround me. If I find them tolerable, I tolerate them; if I find them too obnoxious, I break them. I am free because I know that I alone am morally responsible for everything I do."
A mathematician's best work often comes from seeing connections where others see none.