系统有子系统，子系统有子系统，等等，这是无限的，这就是为什么我们总是从头开始。

自由就是对自己负责。

Changing the destructive things you say to yourself when you experience the setbacks that life deals all of us is the central skill of optimism.

The molecules that mediate pain are ancient, revealing how deeply rooted this sensation is in evolution.

互联网是未来，而未来就是现在。