你不必什么都知道 -

you should not know every thing 你需要适可而止 you should stop in a good time 在一个不重要的方面九十分和六十分并没有区别 you need make sometime for otherthings maybe like the math 你的代码已经足够好了你需要的是让脑子也足够好 code is good enough but mind less