I'll be the first to admit that I don't know exactly what it's like to have autism, but if I were to imagine it based on the things I know (thank you, Psychology bachelor), this would be what I'd imagine. As far as I can tell, the way Christopher's mind works in this book reflects a moderately autistic person's mind very well and it's incredibly interesting to get a bit of insight into that. There are so many little things that are connected to autism, yet can easily be overlooked by the reader if he doesn't know what he is looking for, which makes it quite brilliant to me. 
 Basically, in The Curious Incident, Christopher finds his neighbour's dog, Wellington, murdered with a fork in the garden and he wants to investigate who did it. That is not an easy feat, however; his father doesn't want him 'sticking his nose into other people's business' and he is afraid of straying too far from the paths he knows. His mother passed away from a heart attack a while ago and apart from his father, the only person he really talks to is Siobhan, his teacher at school, who encourages him to write a book on his search for Wellington's killer after he tells her that is what he wants to do. As he works on this mystery, however (just like his favourite detective, Sherlock Holmes), he discovers some other things he definitely did not expect to find. 
 It's remarkable how logical Christopher's decisions and ways of thinking seem to the reader in this book, testifying to Mark Haddon's great writing. There are a lot of rituals and habits Christopher has to stick to in his daily life, as well as things he hates and things he loves that signify yet other things to him - such as the fact that seeing a certain number of red or yellow cars in a row on his way to school determines whether he has a Good Day, a Very Good Day, a Super Good Day, or a Black Day. The reader quickly becomes familiar with these things and it's easy to understand why Christopher thinks certain things or feels a certain way, based on his perception of the world, especially once that world is thrown upside down by the mysteries he accidentally unravels. 
 The Curious Incident of the Dog in the Night-Time is not a detective or mystery story, however, even though it is marked as such on most websites. I do believe you'll end up disappointed if you start reading this book thinking of it as a proper mystery novel. The emphasis is on Christopher's inner world and the way he perceives things, not on the mystery of the dog in the night-time. It's more psychological than anything, which is mainly why I enjoyed it so much. A very interesting and educational read I definitely do not regret picking up.