The past is a shadow, always following, but never catching up.
Mathematics is not about numbers, equations, computations, or algorithms: it is about understanding.
数学不是关于数字、方程、计算或算法的：它是关于理解的。
The boundaries which divide Life from Death are at best shadowy and vague. Who shall say where the one ends, and where the other begins?
真相很少是纯粹的，也从来不是简单的。
The good life is a process, not a state of being. It is a direction, not a destination.