If this seems abstruse, you hear this point of view all the time in political discussions about what the Founders intended when they wrote the Constitution.Various newer approaches say that the author's intent is irrelevant or inaccessible and that what matters is the text and what it says. Or what matters is/are the interpretation(s) elicited by the text. Or imposed on the text by readers.
And so on.
There is even a spiritual or theological tradition about how to read scripture. There is a literal meaning to a story, an allegorical meaning, a spiritual meaning, a moral meaning, perhaps an apocalyptic meaning. All meanings found in the same story. There are rules about when and where you can appeal to such meanings in scholarly discussions, but there is general consensus that all of these are legitimate ways to approach an inspired text. (John of the Cross says it is because the Holy Spirit is not limited like human authors but can put all kinds of meaning into one verse.)
So, what did I mean when I said/implied that my Carmelite books were intended as inspirational and the WhoVille books were intended to be purely entertaining? I mean that, insofar as I had any intention, that was the intention.
On the other hand, especially of the inspirational texts, if someone gets an insight as a result of reading the Elijah book, was that specific insight my intention?
What if their insight is something that I had not thought of, disagree with or even something I would strongly condemn?
I may want to say, "You didn't get that from my book!" But the reader could just as easily say, "That is precisely where I got it. I was reading what you wrote about XYZ, and it flashed upon me that MNO."
And if you think that is far fetched, just think about how people quote scriptures to prove that God wants us to bear arms. Or arm bears, I am never quite sure.
It is interesting to see song-writers and musicians demanding that politicians stop using their songs at rallies. They may want to make sure that such use does not imply support for the candidate or the candidate's views. Or they may feel that such use twists the meaning of the lyrics into something far different from their intention in writing them.
And you thought issues in literary theory had nothing to do with real life!