One of my relatives came home from seminary talking like someone who was brainwashed. None of her opinions were anything like when she left to seminary, and had no arguments to support why this was her new opinion when we spoke to her. She kept these opinions for almost a whole year, by which time she was married and supporting a husband in learning. Then somehow she woke up and became herself again.
Very unfortunate, but not uncommon at all. This is why I say time and time again that Sems are one of the major causes of the divorce crisis (and Roshei Yeshiva say that you should not go out with a girl out of Sem until she has been deprogramed, B’Zeh Ha’Lashon (and I am not at liberty to say who)). I really feel bad for both the girl, her husband (who thought he was getting one thing and it now getting quite another), any children, and both sets of parents. Nebuch 🙁