From the beginning, Scrooge is a stingy old man. It's never stated directly why he is as miserly with his money as he is, but it is somewhat explained in his trip to Christmas Past. He is the son of a strict man who had about as much heart as Scrooge. He was raised in that way, so he is just treating others as he has been treated growing up. As he goes through the past, present, and future trips with the ghosts, he sees himself in a different light. He didn't realize how harsh he had been, and he desperately wants to change. He is given this chance, and with that chance, he completely changes his character. Honestly, most would believe this part to be a fairy tale ending, but with the Christmas spirit involved, it's hopeful for the readers. Perhaps mankind can change from such stinginess to such selflessness. Scrooge then becomes quite close with Tiny Tim and is very giving. I guess it does have a "happily ever after" ending.