what is jay gatsby like in the beginning of the novel and how is he changed in the end?

More than anything else, Gatsby has made his fortune and has come back to win the heart of the woman, Daisy, who said she would wait for him and then did not.  He is reculsive, charming when he does appear, and finds that he cannot win Daisy away from Tom, even thought she seems somewhat enamored with him.  By the end, we see him differently when he is willing to take the "fall" for the killing of Myrtle, even though Daisy was driving at the time.  We feel somewhat sorry for him because there is a piece of him that is still the poor Minnesota child who first was enchanted by Daisy when he was a young military man.  Sadly, he loses to Tom since, as Tom notes, there are things he just does not understand about her.