Curious Incident is written as if its autistic narrator is the author. Most of what I know about autism is from reading Blink, so I know next to nothing. In addition to shaping the actions and relationships among the characters, this premise affects the structure of the book significantly. For example, the chapters numbered by prime numbers, sentences are constructed in a subject-verb manner, there are no similes, only occasional metaphors. It actually feels like the way I would write the first draft of a book where I’d get my ideas down on paper. Later revisions would add more descriptors and vary the sentence structure.
Curious Incident is a fast read that provides insight into how an autistic person processes information. The plot is generally a good one, and there’s even a mathematical proof in the appendix, if you like that sort of thing.
For information on autism see: Autism Society of America