Do you know what you're worth?

For the last couple of weeks I feel like I''ve been hearing the same story over and over again. It''s the same narrative, told by different people; however, the general attributes of each character are the same.  There are two characters, a girl and a boy. The girl is intelligent, funny, giving, and attractive. The boy is intelligent, outgoing, charismatic, and attractive. The two at the beginning fit perfectly with one another. They learn from each other, go out with friends, enjoy each others company and fall for each other. After the first three months they are madly in love. The girl starts to think, he''s the one. But then, something happens.
One night they go out to dinner and they order a bottle of wine. As the girl goes to pour the red wine, the bottle accidentally touches the boy''s glass. He gets angry. He yells. He says things like, "You don''t even know how to pour wine correctly. What''s wrong with you. Did your parents teach you nothing." The girl doesn''t see what the big issue is. "It''s just wine." But the boy doesn''t listen to her. He keeps going. "What are you saying? I don''t know how to pour wine. That I''m stupid? You know what. I''m not even hungry anymore. You''ve completely ruined the entire night." The girl doesn''t know what to to respond. So she sits there and says nothing. She tries to change the subject, to lighten the mood - but nothing seems to work. He''s angry and it''s because of her. She starts to feel bad. And although she know she''s done nothing wrong, she says "I''m sorry. I guess I don''t know how to pour wine." The boy looks up from his meal. "Don''t be sorry, just don''t do it again."
Okay - I know you may be thinking, really, this is such a trivial incident for there to be a discussion let alone a fight. But the truth is that this small hiccup is really just the beginning. The girl passes it off as nothing. It was a weird night. But suddenly it seems that anything she does is wrong. She is reprimanded for almost everything, putting new tomatoes on top of old ones, talking with male friends, going out with her girlfriends. The cycle starts small and innocent, and then before the girl knows it she''s pushed her best friends, family, and career aside to cater to the needs of the boy. He doesn''t like her friends, she stops talking with them. He dislikes her family, she pushes them away. Why does she do this? Is it because she loves him? Of course she loves him, but that''s not necessarily why she stays. She stays because she wants the person she loves to see her as the rest of her friends and family do - as a smart and loving woman. And the only way she knows how to make him see her this way is to give her entire self to him and no one else. In any normal relationship this love would be appreciated and reciprocated - but in this kind of relationship it''s abused. 
Bright women reduced to nothing. Talkative and opinionated women suddenly quiet. All the time thinking, I have nothing to offer. Friends start to get worried and when they do they say the wrong things. Things like - "You don''t deserve him. He''s not a good person." Anyone in this type of relationship is not going to listen. What they''ll do instead is defend the boy, saying things like, "He''s not that mean. And when we''re together it''s different. He''s taught me so much - opened my eyes to things I want to change about myself," and the list will go on. 
I''m not bringing this all up because of one instance, I''m starting a dialogue here because of first hand experience as well as a recent slew of highly intelligent women I know who are or have fallen into the same cycle. I plan to keep talking about these kinds of stories and exploring how not only to avoid these kinds of situations, but also how to survive them. 
Why do some highly intelligent and wonderful women not know what they''re worth and how do they learn to see themselves as others do?