On Theology Network Steven Boyer writes on How the new films subvert Lewis's vision:
"I always felt . . . how hard it must have been, particularly for Peter, to have gone from being high king to going back to high school, and what that would do to him, do to his ego. . . . I always thought that would be a really hard thing for a kid to go through." Adamson acknowledges that this emotional turmoil was “not something that C. S. Lewis really got into,” but as director he wanted “to create more depth for the characters, more reality to the situation.” He wanted “to deal with what all the kids would go through having left behind that incredible experience and wanting to relive it.” This emotional realism was Adamson’s explicit aim, and as a result, the screenwriters who put this scene together were actively encouraged to think about what it would be like to go from “king” to “schoolboy”—not a pleasant prospect, of course, and one to which any of us might react with bitterness and resentment, just as Peter does.
Any of us might react that way—but that is because we have not breathed the air of Narnia. We are thinking like ordinary persons (and worse, like self-sufficient, twenty-first-century, Western intellectuals) instead of like knights or kings. In Lewis’s telling of all of the Narnia tales, the children’s experiences as kings and queens in Narnia consistently transform them into nobler, more virtuous people in their own world. They are not spoiled children wanting to be kings again; they are noble kings who carry that very nobility back into their non-royal roles as schoolchildren. But not so in Hollywood. To be a king at all is to hunger for power forevermore, like a tiger that has tasted human blood and ever afterwards is a “man-eater.” To lose imperial power by being transported back to England is to become a bitter, sullen, acrimonious brat. That is just what Peter has become, and his folly is the driving force behind most of the action in the movie.