I'm sure Mr da Quirm draws lovely pictures, but I for one would need a little more evidence of his amazing genius before we entrust the world to his...device. Show me one thing he can do that anyone couldn't do, if they had the time.'
'I have never considered myself a genius,' said Leonard, looking down bashfully and doodling on the paper in front of him.
'Well, if I was a genius I think I'd know it-' the Dean began, and then stopped.
Absent-mindedly, while barely paying attention to what he was doing, Leonard had drawn a perfect circle.

Author: Terry Pratchett