In 1982, I was in a bad car accident, where I wasn't wearing my seat belt. I hit the windshield fairly hard with my forehead - at least, hard enough to leave lots of tiny glass shards in my forehead that were dug out over the next six months.
I always have assumed that I came back to consciousness after that event... or after several other losses of consciousness that have happened since.
Still, a delusion, fueled by the various simulated reality stories put forward by the media: "Is it possible that I didn't regain consciousness? ...that I'm caught in some strange simulation, designed to keep my mind stimulated, while medical science is working to find a way to bring me back to health?"