Let’s say a guy named Fred is attracted to a woman named Martha. He asks her out to a movie; she accepts; they have a pretty good time. A few nights later he asks her out to dinner, and again they enjoy themselves. They continue to see each other regularly, and after a while neither one of them is seeing anybody else.

And then, one evening…

when they’re driving home, a thought occurs to Martha, and, without really thinking, she says it aloud: “Do you realize that, as of tonight, we’ve been seeing each other for exactly six months?”

And then, there is silence in the car.To Martha, it seems like a very loud silence. She thinks to herself: I wonder if it bothers him that I said that. Maybe he’s been feeling confined by our relationship; maybe he thinks I’m trying to push him into some kind of obligation…