For all the things we share with our brothers and sisters — parents, genes, a childhood — most of us have also wondered at one point or another how we could possibly be related to our siblings. As we grow up, it can be hard to update those relationships that were forged so long ago. You were children together; it can be hard to act like adults together.

More than 200 of you reached out to tell me your sibling stories. I heard from Alix, whose twin sister, Katie, has cerebral palsy. “Every time I reach another milestone in my adult life,” she said, “it feels like something that [Katie] can’t ever get to.” Mike told me about sobering up at 50 — and losing the thing that brought him and his drinking buddy brother together. Paul* reflected on why he feels angry at his big sister, whom he used to look up to. Consuello debated whether or not to let her younger brother come and live with her, after she found out he was homeless. And Megan* opened up about the brother she decided didn’t exist anymore, 30 years ago.

We also heard from people without siblings — like Sabrina, who cared for her mom when she got sick last year. And, I called up my four sisters, all at once, in four separate time zones.

*Name changed