A good mathematician is someone who can see analogies between theorems; a great mathematician is someone who can see analogies between analogies.
一个好的数学家是能看到定理之间类比的人;一个伟大的数学家是能看到类比之间的类比的人。
改变心态只需一分钟,而这一分钟却能改变一整天。
眼睛同时看两样东西,就会看不明白;耳朵同时听两种声音,就会听不清楚。