Once upon a time India was owned by Britain. Then, on August 15, 1947, it didn't anymore. Saleem Sinai was born at the stroke of midnight on the day when India became independent, and for that reason became a) telepathic b) possessing a giant nose and c) the hero and narrator of Midnight's Children. The book traces Saleem's life and the political, social, linguistic, and cultural strife faced the newly independent India.
Sound postcolonial enough for you? It's certainly got enough material, filling over 500 pages. What with the narrator/protagonist who literally embodies twentieth-century India as it achieves independence from the Brits and undergoes the violent trauma of Partition (the splitting of one nation into India and Pakistan), you've got a book completely immersed in one of the biggest postcolonial struggles in modern history.
So don't think we're exaggerating when we say it's got every major theme related to postcoloniality. Seriously, we're not joking here. Linguistic diversity? Multiple and fractured identity? Hybridity? Religious extremism? Racial and ethnic division? Yep, yep, yep. All there—and then some.
Plus, it doesn't hurt to have some seriously genius writing that twists the English language in new ways, plus storytelling that's actually good while being super-literary (he uses magical realism like a guy spinning plates on sticks). We're telling you—there's a reason why this novel won the "'Booker of Bookers"' (given to the best novel in all the years of the Booker Prize) twice.