人类大脑有一种原始的自我防御机制，会否定所有对大脑产生过大压力而无法处理的现实。

不要借钱给你的朋友，除非你愿意把借出去的钱当成礼物。

The natural effort of every individual to better his own condition， when suffered to exert itself with freedom and security， is so powerful a principle that it is alone， and without any assistance， not only capable of carrying on the society to wealth and prosperity but of surmounting a hundred impertinent obstructions with which the folly of human laws too often encumbers its operations.