"Eventually, inevitably, couples lead lead largely overlapping lives. Over time, you start to share more and more things: your friends, your families, a home, a morning routine, a favorite restaurant, an annoying neighbor, that winter when the pipes kept freezing, the cat who liked to sleep on top of the refrigerator, the first Christmas, the forth-fifth Seder, that terrible health scare, the time you got a flat tire on the Pennsylvania Turnpike. And yet, even with this steady expansion of common ground, the enduring challenge of every relationship is to love across difference. That remains true no matter how similar you and your beloved might be or might have become. Love is so often written about analogically—"my luve is like a red, red rose," etc.—yet the point of the beloved, the whole reason that you are in love with her, is that she is like no one else on earth. That includes you: your beloved is not like you."