In the company of friends, writers can discuss their books, economists the state of the economy, lawyers their latest cases, and businessmen their latest acquisitions, but mathematicians cannot discuss their mathematics at all. And the more profound their work, the less understandable it is.
Source: Reflections: mathematics and creativity, New Yorker, 47(1972), no. 53, 39 - 45.
Contributed by: Zaady