你知道得越多，就越意识到自己知道得多么少。
The more you know, the more you realize how little you know.
离散数学和连续数学之间的相互作用是一些最有趣的问题所在。
The past is not dead. It is not even past.
我是一个喜欢在前面的人。
任务必须是困难的，因为只有困难才能激发高尚的心灵。
Never use a credit card for credit. The only kind of credit， or debt， that is acceptable is debt to acquire something whose exchange value is extremely likely to increase， like in a home. The exchange value of most things diminishes or vanishes the moment you purchase them. Don’t be in debt to losers.