我有一个非常简单的想法，如何变富。第一，花得比赚得少；第二，明智地投资差额。

A book is a version of the world. If you do not like it, ignore it; or offer your own version in return.

译文：教导晚辈从小就要有光明磊落的气度和形象，平日还要让晚辈反躬自省，不能没有忧患意识和自我砥砺的修养。赏析：教导子孙后代做人要光明磊落，胸怀宽广，平日要反思自己的言行是否得当。

Childhood is the first and last frontier of literature.

A mathematician is a person who can find analogies between theorems; a better mathematician is one who can see analogies between proofs and the best mathematician can notice analogies between theories.