Realising that you are clueless keeps you on your toes.

Henri Poincare [0] is sometimes called "the last polymath" in mathematical circles, specialisation in subjects increases geometrically with time. Modern CS I would say dates back to the 1930's with guys like Neumann, Turing and Church. A mere 80 years and the subject has just ballooned.

[0] http://en.wikipedia.org/wiki/Henri_Poincar%C3%A9

There seems to be a strong correlation between physicists and good computer scientists:- Knuth, Dijkstra for example.

Seymore Cray worked with radios during WWII and had a very strong background in electrical engineering. He had to rely on Maxwell's equations to analyse signal paths [0]. The bottom anecdote [1] I found highly amusing, very "egg and chicken".

[0] http://en.wikipedia.org/wiki/Seymour_Cray#Technical_approach...

[1] http://research.microsoft.com/en-us/um/people/gbell/craytalk...