I'm obsessed with numbers

When I was in 5th grade, this girl gave me her number. It was the first time I noticed that phone numbers have 7 numbers. Ever since then I have been obsessed with the number 7, also 14 because 7+7= 14. Any number I see, I will start counting it to see if it equals to 7 or 14. It is like some kind of "goal" to me. I have recently started to do this with words I see or hear, when I am watching tv and hear phrases, I start counting the letters, then I do it a few more times to make sure I was correct. Sometimes I don't even wanna count them anymore but it's like my fingers have a mind of their own! When it comes to counting letters I think even numbers are my goal(4,8,10)

Is this OCD? I know this is somewhat common, but why does it happen?

That's very similar to what I have. Yes, I believe it is a form of OCD. Can't say what causes it, but my guess would be it started as a soothing habit which evolved into a neurotic compulsion.

For me, it's obsession with the number 4, powers of 4 (16,64,256 etc), shapes with 4 corners, and coordinate grids where I can mentally connect the corners, always ending with the upper right corner, as it's the last to be connected, and is "positive, positive from an xy point of view. I tap my feet and fingers in fours, trying to make groupings of 16 and sometimes 64 or even 256, but when it's really bad, I just tap in 4s like a machine gun--or rock back in forth-in and out--in 4s.

I kind of wish we with the number obsessions could all form a club.