数学不是一项观赏性运动。

Knowledge is a consequence of experience.

要理解心灵，就跟随它的实际后果。

人性的内涵不缺善性，而人性的需求则不能多添一分欲念。

'Jeff, what does Day 2 look like?' 'Day 2 is stasis. Followed by irrelevance. Followed by excruciating, painful decline. Followed by death. And that is why it is always Day 1.' To be sure, this kind of decline would happen in extreme slow motion. An established company might harvest Day 2 for decades, but the final result would still come.