I do tend to think that there was something about his seeing himself as a caretaker for his ailing mother (even if she was also taking care of him) and how that's influenced things. I particularly liked sp's point that on the one hand he was caring for an ailing mother. On the other hand, a mother is a figure of authority to a boy, and this may influence his urge to care for women of strenght who are in a destructive phase.