Re "a little bit OCD", yes, some people will just bandy this phrase around and it means nothing, however, you don't really know whether they mean that they do have OCD, but that it is mild or controlled. I think that's the bracket that I fall in to. No one except my immediate family would have a clue.
As a child (before OCD was ever talked about), I had to perform certain rituals, otherwise I was convinced that everyone would die.
As an adult, I still do something OCD related about once a day. It ranges from checking that oven knobs are off multiple times, to not allowing myself to swallow if I am looking at something "bad" like a coffin, otherwise I have to cough the bad luck out. I cannot walk between bins and houses, I have to go in to the road to avoid that. I can't switch a light switch off if I'm thinking of a loved one, lest that extinguishes them, I can't lift my feet off the floor when I get in to bed, unless I am thinking a positive thought. Don't even get me started on how long it takes me to leave the house if we are going on holiday.
To the outside world, I look totally normal. My rituals don't bother me, they just fit in to my daily routine. I am not debilitated by any of it. And yes, I've sometimes thought to myself "I'm a bit OCD" which I think means (to me anyway), that it's there, but it's mild. I feel very sorry for those who have it more intensely, to the point it messes with your life.