Consciousness is to our universe as a video game player is to the in-game universe. Some games even call player connections "souls" or "minds" - a character belonging to a player who's lost connection may be "unconscious" or a "zombie".
Game characters, unless they've been made to break the fourth wall, have no idea what this means or why this happens.
I don't mean to imply our universe is a video game, since it would be games all the way up.