To break up with someone is to lose the imagined future you would create together, but you would always share the landscape of your collective past. If Sam could not remember, I would be alone in that landscape.

His doctor said we had a window of opportunity to restore his memories and the more we could help him recall now the less permanent damage might be. I visited most weeks. So did his closest friends.

Part of the pleasure — and conflict — in collective reminiscence is the inevitable discrepancies. I yearned for those discrepancies. I wanted an account of our story to exist independent to mine, but there was little I could do to prevent my account of our past polluting his own.

Read more in the New York Times.