okay this theory has very little proof but I think it would be a very suprising twist to an already suprising show.Well when Simon gives Marcy the doll it appears as if he left her earlier and came back.Well what if Simon had more then one memory and knew a secret group of humans who survived by a chamber.Maybe even Betty was one of those humans.(It would kind of explain finn and his ancestory.).well long story short whenever he leaves marcy he has one reality and when he leaves the humans he has another.It would be cool but I know it is highly unlikley