Potential Changes in a Character

First impressions can often be misleading when we are looking through different types of literature and films. There are a lot of authors and directors that do this to create a false antagonist. In the cartoon film, Ratatouille, the director shows that there are two different types of antagonists. One is against the main character and the other is a very negative person who doesn't seem to like anyone or anything at the beginning of the movie. Throughout the rest of the movie though, it seems as though this character changes and at the end, he ends up helping the main character, giving him an excellent review and helped save their restaurant. Is this a change that we may see in our everyday lives? Can it happen for anyone or only people who are devoted to the change?