Well, the first rule is that you can’t really know anything if you just remember isolated facts and try and bang ’em back. If the facts don’t hang together on a latticework of theory, you don’t have them in a usable form.

勤俭了就有了约束，有约束了就会各种好事都做；奢侈就放肆，放肆则各种坏事都泛滥。