The past is not dead. It is not even past.
解决数学问题的过程往往比解决方案本身更重要。
If you don't design your own life plan, chances are you'll fall into someone else's plan. And guess what they have planned for you? Not much.
真正的智者,是知其然,也知其所以然。永远明白自己在做什么,要做什么!清醒,问心无愧,活得明明白白!