I have terrible OCD since my injury and one thing that’s good about that is there’s no WAY any OCD would let me forget where I was hit. Nope, I would remember all the details. I would assume... if you hit your head, you’d know the exact spot. You’d focus on the exact spot, the lingering buzzing of the hit.
This sounds bad, but use your OCD to your advantage in this case and say, “if I really hit my head, I’d be so aware of the location, I wouldn’t have to ask.”