出自汉·桓宽《盐铁论·殊路》。镂：雕刻。如果没有内在的工夫，而只学习其表面，即使有再好的老师和朋友，也还是如同在油脂上作画、在冰上雕刻一样，只是浪费时间和功夫。

What we learn from history is that people don't learn from history.

"We think we’re the ones who notice things, but really it’s the things that notice us."

不经历风雨，怎么见彩虹。