I've always thought of it this way..
Michael had a crush on her since he was very young, as he got to know her basically had childhood love with her, meanwhile she thought of him more so as a son type love.. As he got older I believe his love for her stayed the same while she may have gave him the impression of something more.. Or he may have taken it that way when she'd call him 'sexy' and maybe be flirtatious in some regard.. (IDK it's just impression I get).. I believe that F'd with Michaels heart and he thought his love/fantasy of her could come true and it never did..
He definitely seemed hurt by her not recuperating the same affection - just don't know where the pain came from.. what she did to lead him on.. that remains a mystery.
