Mark Haddon, who has worked with autistic children, has created a unique narrator to tell this story. At first glance, an autistic child whose fantasy is to wake one day and find he's the only living person left on earth would seem to be an unlikely narrator. We quickly come to understand Christopher Boone and his understandings and misunderstandings of how the world works. We sympathize with the adults who must suffer his fits and practice extreme patience with the minute details with which he orders his life. Christopher's father is the most patient with him, even if his manner is gruff at times. He quickly forbids Christopher to ask anyone questions about Wellington's death and to promise to let the matter die, which Christopher does, within the specifics of his promise. The questions he's already asked, though, and the people he's already met have put events into motion that will eventually send him on an adventure that will challenge all of his skills to cope with the world that he is especially challenged to understand.
Because Christopher understands even less of the world than most 15-year olds, the result is that seeing the effects of emotions, lies, and intrigue of the adult world through his eyes lets them hit even more powerfully. Since he sees all this in his non-judgmental perspective and only how they affect the careful order in his world, the flaws of the adults are heightened by their disregard for the effect they have on Christopher while also being tempered by the fact that his autism has placed incredible stresses on all their lives. Christopher is more than just a different medium for seeing the world. In Mark Haddon's capable hands, he quickly becomes all too real, and while he can be incredibly frustrating, he explains his world in a way that makes perfect sense. When events unfold that threaten his carefully maintained world, his quest to solve the problem is as adventurous and dangerous as any literary character. To Christopher, it's something he just must do.