每个数学问题都有解答；挑战在于找到它。

I quite agree with them that it is not an ennobling experience. Poverty entails fear, and stress, and sometimes depression; it means a thousand petty humiliations and hardships. Climbing out of poverty by your own efforts, that is indeed something on which to pride yourself, but poverty itself is romanticised only by fools.

欣赏和喜欢你拥有的东西，而不是你没有的东西，你才能快乐。