I told a friend that I was going to write about being single. “But you’re not single!” she said. “You have no idea what it’s like to live alone.” She’s right. I’ve lived with my “boyfriend” since I was 22—and I’m 66 now. From the beginning we’ve had a joint bank account, and everything that’s his is mine and everything that’s mine is his, including an apartment and two children. It’s a fine point, I admit, but there’s a reason we haven’t gotten married. I never wanted to be half of anything—not even someone’s “better” half. As a child, when other girls dressed up in their mothers’ slips for make-believe weddings, I hung back. And when someone asked me what I wanted to be when I grew up, I said, “A hermit.” Even then I wanted to feel whole, on my own, untethered. In the end, life gets messy, and you get tied down. So, yes, my singleness is now a mere technicality. And lately my boyfriend and I have been advised to get married for estate-planning reasons. I would never have gotten married for love. But for money? I don’t know. I’m thinking about it.