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.
