Often the adult book is not for you, not yet, or will only be for you when you're ready. But sometimes you will read it anyway, and you will take from it whatever you can. Then, perhaps, you will come back to it when you're older, and you will find the book has changed because you have changed as well, and the book is wiser, or more foolish, because you are wiser or more foolish than you were as a child.