Another confusing conversation

Last week, S at work and I talked horses. She grew up competing and we talked about a lot including Chosen by a Horse and the new one Chosen Forever. I told her I would bring in the second one.

Here is the conversation we just had:

ME "I am on page 239."

S slight delay and puzzled look "Do you have 2 of them?" (Thinking I was still reading the book.

ME slight delay and also puzzled look "I am ON page 239."

S "How do . . . do you have 2 of them?"

ME Light dawns on Marblehead, "I am IN page 239 of the book, I AM IN THE BOOK."

S slight delay light dawns on Marblehead "Oh, you are IN the book. You ARE page 239."

Language is such an interesting tool, which sometimes works and sometimes does not. I am sure this is MBTI related.