Subject of the enunciation, tomorrow

I found this very early in the novel Tomorrow, and Tomorrow, and Tomorrow by Gabrielle Zevin.

He found himself uttering a series of “excuse mes” that he did not mean. A truly magnificent thing about the way the brain was coded, Sam thought, was that it could say “Excuse me” while meaning “Screw you.” Unless they were unreliable or clearly established as lunatics or scoundrels, characters in novels, movies, and games were meant to be taken at face value—the totality of what they did or what they said. But people—the ordinary, the decent and basically honest—couldn’t get through the day without that one indispensable bit of programming that allowed you to say one thing and mean, feel, even do, another.

A great example of the difference between the subject of the statement and the subject of the enunciation.