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

Every mathematical problem is a window into a deeper understanding of the world.

释义：做事情必须踏踏实实，不要追求浮华的虚名。

If time travel is possible, where are the tourists from the future?

"Every story is a journey, and every journey changes the traveler."