One of the ways an author plots and plans what happens to a character and how that character reacts is through The Hero's Journey. According to Joseph Campbell, (The Hero With A Thousand Faces) the myths and legends from around the world at many different times in history all share common stages and fundamental structure. The Hero's Journey.
There's actually 17 steps in this journey, but not every hero takes all of them. Some tales only contain a few elements. It simply depends on what the character needs to learn and discover--in their own heart and head. For authors, The Writer's Journey by Chris Vogler, discusses this mythic structure for writers.
It's fun and educational to pick out the different stages in the hero's journey in movies and books. But first, you have to know what to look for. Glove and Boots have a quick and delightful explanation.