How has Christopher changed by the end of the book?

Christopher shows a growing desire for independence throughout the novel, and through much of the novel we watch as Christopher gains the confidence to assert himself. He shows his yearning for independence in a few ways, rebelling against his father by disobeying his orders, for instance, and fantasizing about doing whatever he likes and taking care of himself in his recurring dream of being one of the few people left on Earth. He also begins planning to go to college, and to live on his own there. As Christopher overcomes the various trials he faces, he gains confidence in his abilities and gradually becomes more self-sufficient. This process culminates in a difficult journey to London that Christopher undertakes by himself, a feat that represents a significant triumph for him since he has never traveled by himself. At the end of the novel, Christopher feels he has overcome his challenges, and he feels ready to be on his own.