I came upstairs, for a nap of my own, when I saw through a crack in the door the nanny singing my 5-year-old to sleep. (Is she too old to need such care? Are we ever too old to need such care?) It felt so intimate, so private, like I’d stumbled onto love in its pure, naked form. I got embarrassed and turned away quickly, then, for a reason I can’t explain, I cried myself to sleep.