My friend Paula turned 50 last year. It’s been more than a decade since she and her husband realized it was time to accept that they wouldn’t have children. For ten years she’s been working through the mess—the grief, the anger, the sadness, the despair, the big, big question of “what am I am going to do now that I won’t be a mother?” And because her older brother was a confirmed bachelor, Paula also felt pressure from her parents to produce a grandchild, even though they never said it out loud.

But that was a long time ago. If you ask Paula now, she’ll tell you she’s “cured.” She’ll tell you that, most days, she doesn’t think about the fact that she’s childless. She and her husband travel, they have a broad circle of friends, she’s been able to hop on career opportunities that would have been difficult with small children. She enjoys her friends’ children and she enjoys handing them back to their parents. In her candid moments, she’ll say her life worked out better than she’d expected and might not have been so great if she’d had the children she once so desperately desired.

Life is pretty good for Paula.

And then her brother fell in love, married, and shortly thereafter announced he would become a father. Paula called me in tears. She was utterly blindsided by her tearful reaction.

“I thought I was over this,” she said. “I wouldn’t swap places with my brother for anything. A newborn at 53? Nightmare.”

She told me her parents were over the moon, that her mother was telling everyone that she was going to be a grandma. “At last,” she told people, giving Paula a meaningful look.

“At last?” Paula said to her father. “What’s that supposed to mean?”

And that’s when her dad opened up. He admitted how “difficult” all this waiting and longing had been for them. He’d felt left out too, he told her.

She understood, but his confession found its way deep inside Paula, to that one small dark spot that had yet to heal, and poured salt into all those old—and now reopened—wounds. The guilt and shame that consumed her in that moment was overwhelming, and the tremendous weight of that was part of what took her by surprise. Her brother had made her aging parents happy, had given them the thing she couldn’t. The family torch had been passed and it wouldn’t be to Paula.

When I talked to Paula again a couple of weeks later, she assured me that she was going to be okay. She said a part of her was looking forward to being an aunt and that her big grown-up self was happy for her brother and her parents.

“But,” she added, “people always ask how long it takes to get over not being a mother. I always thought seven or eight years was about right, but now I think maybe the answer is ‘never.’”