OCD affects aspects of human experience that most people don't think about, or only fleetingly. It's not that OCD is totally alien, but it is more severe than what people without OCD experience. I have OCD but don't usually check switches and such. But when leaving on vacation, a few years ago, I was halfway out of town and couldn't remember if I locked the door, and went back to check. Everyone has had a day where they aren't sure, and go back to check. Sometimes special circumstances like vacation will make you more aware of the consequences of an unlocked door.
Usually someone without the compulsion to check doesn't need to remember if they locked something or turned off a switch or a knob, because they do it, and move on
without even thinking about it. It feels "done" but it's barely conscious, and they flow into the next actions of their day. OCD can disrupt every aspect of the flow of life. Someone with OCD can turn off the light switch, and stand there in the dark and still not be absolutely certain they turned it off, because they get a surge of anxiety that is gut wrenching, and a host of possible feared consequences, ie. "If I don't turn this off, a circuit could short and burn the house down. So I'd better keep checking."
The other day I watched my husband search for a muffin recipe online. He looked at a couple, one fit his ingredient list, and he hit print. He knew he was done. I could even say he "felt" done, but it's so a part of him that he doesn't really feel it as much as keep moving in the momentum of what he wants to get done. Part of my OCD is not feeling finished, not feeling I've fulfilled my goal, and I'm well into page 10 or more on Google when looking for a recipe. It's like I don't have an "off switch," and I am very likely to feel anxious if I don't feel "just right" or "done" and ironically, my OCD pretty much guarantees I won't get that feeling, no matter how much compulsive searching for the perfect thing.
Even when I find something that fits my criteria, I don't believe it, because I want to be certain that it's the right thing, and I'll feel anxious if I take the chance of printing something from page one. OCD isn't about logic. This can frustrate both the person with OCD and their friends and family. There is a tendency to assume if you explain the illogic, that this will solve the problem. "You are standing in the dark. Of course the light switch is off." "You've checked 5 review sites, and they all recommend the same product--why do you have to keep looking?"
I've always been fascinated by phenomenology--the attempt to understand what someone's experience is from the inside, the lived sensations of consciousness. OCD is that moment of wondering if you locked the door, and thinking you probably did, but having dire visions of thieves in your house while on vacation. You feel anxious. You don't want to ruin your vacation worrying about this. You drive back to check the door. But OCD will keep generating those moments of stabbing fear, even after you've checked. Did I really check? How can I be sure? There's no stopping point.
Cognitive Behavioral Therapy can get hung up at this point if the instruction is to guess the probability of something bad happening, and how much of it would be your responsibility--it could be .00001% and the OCD is still going to be clamoring about no risk being acceptable. For me Exposure Therapy has involved choosing something off the first page of Google, even if I break into a cold sweat, to help retrain my brain recognize that I'm done and can move on. I spent years waiting for fanfare and illuminated signs that a decision was right so I wouldn't have to feel anxious, but I am learning that most decisions don't get that kind of certainty, and that I can actually live well in spite of this.
