I think that OCD is like looking after a little cluster of needy, whiny pets for a relative with a very violent criminal record who’s gone away indefinitely. You don’t want them there, they are just irritating noise that gets in the way of everything you do, but you have to care for them. You have to feed them every time they squeak or they will drop dead, and that would make the relative very angry and they would probably come and bash you with a huge steel meat tenderiser for an extended period of time.
No one wants that.
So you take the cluster of needy, whiny pets everywhere with you. And they dash off in all directions following every scent they find, they run around your feet trying to trip you up, and they all want all of your attention all the time. And you must do what they want or something terrible might happen. You know that the relative will probably never come back for them; it is possible that you are doing all of this for absolutely no reason, but there is no way of knowing for sure so you do what you think is necessary to prevent that potential meat-tenderiser-related torture.
And it just goes on and on. And it is exhausting. You are very aware of how ludicrous the situation is, but letting them die – or even passing the responsibility over to someone else – is simply not an option because you are so completely terrified of the potential consequences.
OCD is repeatedly performing some insane task which you know is totally illogical, to prevent a consequence that will probably never happen but it’s so scary that you are not willing to take that risk.