After fifty years, you stop arguing about the curtains. Not because you have agreed about the curtains. You have simply moved, together, to a place where the curtains no longer matter.
What matters, I have found, is the furniture. Not the furniture itself — the specific chairs and tables, which change and are replaced and are eventually forgotten — but the fact of it. That there is a chair where someone sits. That the table has a particular orientation toward the window. That the lamp on the left is hers and the lamp on the right is mine, and that these facts are no longer discussed because they are no longer in question.
A long marriage is mostly furniture in this sense. The deep arrangement of two people in a shared space, each knowing where the other goes, and when, and with what degree of silence. It is not romantic. It is better than romantic. It is the thing that romance, if it is lucky, becomes.
The most intimate thing I know about her: she turns the page of a book with her left thumb, always, even now, even when her hands ache. I have noticed this for fifty-two years. I have never mentioned it. I never will. Some knowledge is not for speaking.
We do not agree about the curtains. We have not agreed about the curtains since 1978. But we have sat, every evening for half a century, in the same room with the same curtains, and this is, I think, its own kind of agreement.