Christopher's first person narration plays an important role in this book. It allows the reader to obtain a deep insight into Christopher's way of thinking and in turn show's the reader the world through his eyes; though this narrows the story down to one in particular point of view, Christopher's. Due to this there are many limitations placed upon the book regarding themes and other characters.
As Christopher suffers from Asperger's Syndrome it would be difficult to describe his character in detail with a third person narration since in this type of narrative the reader needs to know what's taking place within in his mind or the story would be even more difficult to make sense of. A good example of this is in chapter 11 while Christopher talks with the police for the first time. If this book were written in third person narration the scene would be described as a police officer asking a child a few questions, then helping the child to his feet and finally the child punching the officer.
From this description the reader could not possibly understand why he would hit the policeman and Christopher would unjustifiably be accused of being violent. Without reading that he was becoming confused and agitated, or understanding that because of his condition he doesn't like being touched the reader cannot understand why he did what he did. The bread factory analogy is also an important concept to help explain his behaviour later in the book about how he can only process so much information at any given time. Such an analogy could not be effectively portrayed without this first person narration by Christopher himself.
The world is seen quite differently by Christopher and since the story is based around him it would seem rational to see it the...