Have you ever wondered how some people go down hill big time?

i just saw elizabeth montgomery on a lifetime movie (not that i watch the lifetime channel very often lol!) and she was an awful nasty looking old hag? i remember when she played on bewitched back in the day she was pretty hot? what happened to her? i mean jacalyn smith from charlies angles is still hot, and even goldie hawn is still hot, so what caused this woman to take such a nose dive?