Remember, too, that his mommy was really the only person, woman or otherwise, in his life, who loved him unconditionally. She listened to his craptastic poetry, told him how wonderful he was, and supported his interest in Cecily. When he vamped her and she turned on him, it froze him at that stage: in trying to help the only caring woman in his life he made a huge mistake and and he feels he must pay penance by continuing to fall in love with women who have loose screws, and he might feel undeserving of a normal, loving relationship.