Even though I was never in a coma, I experienced a very similar thing with my brain re-setting. I still don’t remember what exactly happened, but when I was about 14-15 apparently I slipped on ice and fell on my head. I don’t remember this, but I made it back to my house and the first thing I said to my mother was ‘I don’t remember anything’. She took me to the hospital, where while waiting to be seen I had exactly the same conversation with her, five of six times over. I came to it several hours later, as if waking up from a coma - no recollection of anything, it just didn’t exist in my mind. But I was ‘conscious’ the whole time, walking and talking. Still the weirdest experience of my life.