宫殿中可以避世全身。何必深山之中蒿庐之下。
在朝堂上也可以当一名隐士，何必非要到深山老林中去呢？
马跑不起来都是因为太瘦；人不能扬眉吐气就是因为贫穷。
Nature is the best teacher; it has already done the experiments, we just have to interpret them.
Don't bother just to be better than your contemporaries or predecessors. Try to be better than yourself.