So, erm, "believe the reality".
This is a very impressive read, is the reality, as it does a lot of what mainstream teen and tween fiction still struggles with. Its focus is courtesy of the first person narration from Fly, a secondary school lad with cerebral palsy, a down-on-her-luck single mom nearing retirement from being a cleaner, a carer while at school, and a bundle of assumptions people lay on him. First they assume that with a broken body comes a broken mind, then they decide he's a maths savant – they even believe they can get away with calling him Fly, which isn't his real name, but everybody just uses it.
So Felix, not Fly, has a lot to be bitter about. But having his back, steering him through all the hours when he can't be bothered to look up and see pity, inanity and everyone's constant struggle to avoid the alleged struggle of talking to him, is "Don Quixote", the hefty and ancient volume about chivalry, dubious assumptions and justice. This is yet one more unexpected layer on the whole piece, and who knows – people may well turn to more than the exam notes to check it out as a result.