Four years after we first met, the man Sara had been seeing was offered a job in Boston. They dated long distance for a year. But then they had to make a decision; he was intent on staying in Boston, even though it was not a city that offered her much professional opportunity.

Watching Sara wrestle with her choices was painful. It was the kind of upheaval, in our late 20s, that was messy enough to make me consider whether early marriage might have been wise after all. When we’re young, after all, our lives are so much more pliant, can be joined without too much fuss. When we get older, the infrastructure of our adulthood takes shape, connects to other lives. The prospect of breaking it all apart and rebuilding it elsewhere becomes a far more daunting project than it might have been had we just married someone at 22, and done all that construction together.

The day Sara moved to Boston, after weeks of packing and giving away her stuff, a bunch of friends closed up the U-Haul and gave long hugs and shouted our goodbyes as she drove off. When she was gone and I was alone, I cried.

Make no mistake: I believed that Sara should go. I wanted her to be happy and I understood that what we wanted for ourselves and for each other was not only strong friendships and rewarding work, but also warm and functional relationships with romantic and sexual partners; both of us were clear on our desires for love, commitment, family. Yet at the time, I was so gutted that I wrote an article about her departure, “Girlfriends Are the New Husbands,” in which I contemplated the possibility that it’s our female friends who now play the role that spouses once did, perhaps better than the spouses did.

Historically, friendships between women provided them with attention, affection and an outlet for intellectual or political exchange in eras when marriage, still chiefly a fiscal and social necessity, wasn’t an institution from which many could be sure of gleaning sexual or companionate pleasure.

Because these relationships played such a different role from marriage in a woman’s life, it was quite realistic for commitments between women to persist as emotionally central after the marriages of one or both of them. Even the happiest of married women found something in their associations with other women that they did not have with their husbands. As Elizabeth Cady Stanton, devotedly wed and mother of seven, once said of her activist partner, Susan B. Anthony, “So closely interwoven have been our lives, our purposes, and experiences” that when separated, “we have a feeling of incompleteness.”

SIX months after she moved to Boston, Sara came back.

She came back because the relationship she’d traveled to Boston for wasn’t fulfilling. More important, she came back because the life she’d left in New York — her work, her city, her friends — was fulfilling. She came back for herself. She says now that it was a New York job listing that was the beacon: “It was telling me to return to the life that fed me, my circle of friends, to return to myself.” I was sad that her relationship hadn’t worked out, but happy that she had built a life on her own that was satisfying and welcoming enough to provide her with an appealing alternative. And I was thrilled to have her back.