不经过一年中最寒冷的时候，无法知道松柏是最后凋谢的；不经过艰难的考验，无法知道一个人是不是真正的君子。
实现明天理想的唯一障碍是今天的疑虑。
The true measure of our success isn't in tons extracted, but in lives impacted.
A mathematician is a person who can find analogies between theorems; a better mathematician is one who can see analogies between proofs and the best mathematician can notice analogies between theories.