It could be a novel that delves into a mystery or a deep emotional journey. Maybe the last thing he told me is a clue to a big secret, like in many mystery novels where the final words of a character set the whole plot in motion. It might also be about relationships and how that last communication impacts the characters.
I'm not sure specifically as I haven't read it in detail. But it might be a story centered around the last statement made by a particular person, perhaps exploring the significance of that statement and the events that follow from it.