A quotation by Lipman Bers

... mathematics is very much like poetry ... what makes a good poem -- a great poem -- is that there is a large amount of thought expressed in very few words.
In this sense formulas like Bers1.gif or Bers2.gif are poems.
Quoted in D Albers, G Alexanderson, C Reid, More Mathematical People

Mathematics is a collection of cheap tricks and dirty jokes.

There are two kind of mathematicians, smart ones, and dumb ones. I am one of the dumb ones.