After my bypass surgery, after the first week, my son and grandson came to see me. (It's over three hundred miles away) I looked up to see a very tall man (I thought he was a new doctor) and a young man standing there. Bill said, "Mom, don't you know me?"
I laid it onto being medicated, but for that instant, I didn't know either of them.

You likely feel secure enough to sleep deeply, but all the medical treatment you went through could be causing it, too.