出自汉·桓宽《盐铁论·后刑》。锄去田里有害的杂草，禾苗就可以健康地生长；惩罚为非作歹的恶人，百姓就会感到喜悦。

The harder you work, the luckier you get.

No one is altogether to be blamed for the defects of his nature; but he is blameworthy if he takes no pains to correct them.  

在数学中，从困惑到清晰的旅程是最有价值的体验。