Just out of curiosity, is this your own self judgment or someone else's? I have been told frequently that I overthink things but every time I ask the person doing the asking what the appropriate level of thinking is and how that is determined, they can't tell me.

I played poker professionally for twenty-four years, and have written a book on no-limit Texas Hold'em. The part of my book that has received the most critical acclaim is the section on reading people. I read them, then predict the outcome determining whether to check, bet or call. As for chess; I am a chess master - this over-thinking (as you call it) comes in very handy. (note the sunglasses - very poker-esque)

Is it causing you more difficulty in your life or does it cause you less difficulty because you think things through so thoroughly? Therein lies the answer.

Everyone doesn't. But I don't consider it an obsession - at least for me. As for the OCD - I've been dx'd at one time or another with five personality disorders...they haven't decided I have OCD yet.