形容世事短暂如春梦，人情淡薄如秋云。

I've learned that it's okay to be vulnerable.

道德的人和荣誉的人之间的区别在于，后者即使在不光彩的行为奏效时也会感到后悔。

In the world of physics, we often find that the simplest questions are the hardest to answer.