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.
Prolonged contact with the computer turns mathematicians into clerks and vice versa.
In science, the credit goes to the man who convinces the world, not to the man to whom the idea first occurs.
In mathematics, you don't understand things. You just get used to them.