数学不是关于数字、方程、计算或算法的:它是关于理解的。
不要担心自己如何开始或是在哪里开始。只要你继续前行,你就会比你开始时更加成功。
In republican governments, men are all equal; equal they are also in despotic governments: in the former, because they are everything; in the latter, because they are nothing.
You have to be able to admit when you're wrong and move on.