如果你是战士，别为你自己的自由而战，而要为你战友的自由而战。这样，战争对你俩来说，就会更加鼓舞人心。

Profitability and purpose are not mutually exclusive.

生活就是要冒险。如果你不冒险，你永远不知道自己能做什么。

I don't have any particular recipe [for developing new proofs] ... It is the reason why doing research is challenging as well as attractive. It's like being lost in a jungle and trying to use all the knowledge that you can gather to come up with some new tricks, and with some luck you might find a way out.