This was clearly written as a response to the stories about chosen ones and prophecies. Because the distain that the story holds for those particular tropes is evident in almost every line. The book also plays a lot with puns and mispronounced nouns, the way that quite a few children's novels do. So that you have things like black windows running around in Webminster Abbey. It was enjoyable, and I really did like the message that it's choices that make you who you are, not prophecy.