That is a cool question. I agree with you that a book can read you. I also agree good books do tell you something about yourself where you can grow and add something to who you are.
I just finished reading this fiction "The Brief and Wondrous World of Oscar Wao" by Junot Diaz and it was incredible! (If you want a good fictional novel, this is a good one with many underlying politics and lessons about humanity; it also won a pulitzer prize) I went to the listen to the author himself, Junot Diaz, at a book talk. He mentioned how readers often times accept authoratative writing to always be true (like textbooks, factual stuff) So in his wrtiting he incorporates an authorative style where what he writes is factual but how very well it could be false. My point is, often times as readers we accept what we read (if it sounds right) and don't take the time to figure our if it is indeed correct.
In that respect I think that a book does read you, it knows and presumes that you will accept what is written in those pages. Maybe I am interpreting the question differently than you. I could be wrong. Let us look at the facts. How many times do we challenge what we see in our history books? Not to say that our history books are wrong, but it has happened before. Did Hitler not do it? In many nations around the world do governments omit what they do not want the public to know? The same way we can read literature or textbooks and take it apart to learn from it, is the same way we can be passive about it and take it for what we see.Though it can go both ways, I feel that most of us a general public are passive to what we read (if reading at all). Which is how I agree with you in that a book can be the one reading you. An author can presume that we will be passive and in that case who is doing the reading, the author (book) or the reader?
Very nice question my friend, and I support your take on it :)