This is probably an unnecessary addition, but OCD is missed in cases like these because it's deeply misunderstood by most people.
It's talked about like being obsessively neat or repeating pointless tasks is the main part of it, when really those are just potential symptoms.
The main thing behind OCD is not being about to turn off a thought. There's a thing where most people can just stop thinking about something. If it's over, it's not relevant, it doesn't matter anymore, people can turn their attention away. For OCD, that mechanism can get stuck. And some thought that was supposed to just temporarily pass through your head just stays there. An image of an object rotating. An anxiety about something bad happening. A wish that you made on a dandelion. These are all things that have at some point gotten stuck in my head, sometimes for years at a time.
The compulsions, the rituals, are the person trying to address the thought so it can go away. After all, if you're worried about the door not being locked you can check the lock. But for someone with OCD, that doesn't make the stuck thought go away. So they check it again. And again. And they made a ritual, maybe if I check it exactly five times, I'll know that it's locked and I can let this worry go.
It helps a little. It feels like you're doing something. But it doesn't solve the problem. Actual therapy for OCD involves not doing the compulsion. Instead, you ignore the thought, move around it, try not to give it space in your life. Your mind won't let the thought go normally, so instead you fill yourself with other thoughts. Other parts of your life.
It's not easy at first. Your mind fights you on it. But as you get practice, it gets easier. You learn tricks around your own mind, ways to look at the thought and go, hm. I guess I'll go distract myself now. It does get better. I promise
