心是脆弱的东西，容易破碎，但也有着难以置信的韧性。

The first love is only a little foolishness and a lot of curiosity.

The best way to create interest in a subject is to render it worth knowing, which means to make the knowledge usable.

生活是一部没有作者的小说。

来时惊动很大，走时没有任何声响。

The beauty of instrumental variables is that they allow us to see the world in a new light.