Adam is a man with Asperger Syndrome. His treatments get better when he falls in love with his neighbor, but at the end of movie, he isn't successful to live with her. Why? He is too much honest! He needs her for his Social fears. She wants a man who loves her, not only for his needs. She wants some thing more than caring him.
In my opinion, he is a true lover. She makes a wrong decision. He never lies or cheats. His treatments could get improved. He would learn how to love a girl for herself.