A mathematician is a device for turning coffee into theorems.
The purpose of life is to conjecture and prove.
There are three signs of senility. The first sign is that a man forgets his theorems. The second sign is that he forgets to zip up. The third sign is that he forgets to zip down.
I know numbers are beautiful. If they aren't beautiful, nothing is.
Mathematics is not yet ready for such problems.
If numbers aren't beautiful, I don't know what is.