The one who speaks and the one listens, that is the “I” and the “you” implied in a sentence, are theoretical entities. That is, they may be actual beings as, for example, the person who wrote this and the person who is reading it, but the sentence itself exists even when no one is reading it and when no one is saying it any more.
This writing stays there somewhere without any real being saying it and no one reading it. It reads as if there is an author and an audience, even if no one witnesses it, but the author and the audience become actual only when someone reads it. It is the reader, then, that gives life to the writing, making the author and the reader actual, real.
And even then, the one who writes when this paragraph is being read is not the person who wrote it, but the theoretical entity implied in the mind of the person who reads it. I, the writer, am only an entity implied by these words you read. I am a figment of your imagination, only part of you created by you through the mechanism of this language, by the magick of these words you read. “I” am only implied by these words.
Your mind creates me in your mind, yet I could not exist in your mind as the author of these words without the existence of these words, these words that never really existed until someone read them, these words that were not real until now, when you are.