Answer:
He still wants to be a doctor at the end of the story, but he no longer believes that becoming a doctor is an impossibility.
He still does not understand the hard work that goes into becoming a doctor at the end of the story, but he is no longer willing to try.
He does not know what he wants to do with his life at the beginning of the story, and he still struggles with this at the end.
He has clear ideas about how to achieve his goals at the beginning of the story, and he still has these ideas at the end.