I kind of agree with survivor. Certain occupations lend themselves to its exacerbation. I have heard pharmacists are quite susceptible. By the way, people with OCD are, indeed, usually of above average intelligence.

Occupationally, I have done very opposite type things. One side is me the musician and artist and the other is doing things like proofreading and transcribing - the grammarian. I definitely enjoy creating and expressing myself, but I like logic and language too.