I was diagnosed with OCD well into my thirties. It was always there I guess but it never rared its ugly face until after I had kids.
My wife would buy magic sand, and slime for the kids. Things I've never really interacted with. And seeing them play with it would drive my absolutely crazy even though they weren't always necessarily making a mess. I'd always need reassurance from my wife that she had everything contained and they wouldn't dirty up the furniture or walls.
One day I came home from work and they were finger painting and I absolutely went bonkers. I could not for the life of me put into words why these kinds of things unnerved and bothered me, but it persisted to the point where I had to see a professional because I knew something was wrong.
Saw the doctor, diagnosed me with OCD after a couple weeks, gave me some anxiety medications that made me nauseous 24/7, and I stopped taking them. I also stopped seeing the doctor.
I've just trained myself the last three years to not let these things bother me anymore, my wife is more understanding when I blabber on about the kids jumping on our bed with dirty feet, or when they come back into the house after spending an afternoon on the beach, but for the most part, I catch myself before I allow the anxiety to sink in.
I am the black sheep 
"of course I'm crazy, but that doesn't mean I'm wrong."-Robert Anton Wilson
