记忆是脆弱的，生命的空间如此短暂，转瞬即逝，我们永远无法看清事件之间的联系。
"Memory is fragile and the space of a single life is brief, passing so quickly that we never get a chance to see the relationship between events."
The power of abstraction is that it allows us to reason about systems at a higher level, without getting bogged down in the details.
——《民族主义第一讲》
When the last fish is caught, mankind will realize money can't be eaten.
关于人性，唯一真正知道的是它是会变化的。
农时：指春耕、夏耘、秋收三个时令。与其等灾荒来了再想办法补救，不如早防备灾荒，而防备灾荒最好就是抓住农时。