What’s the last thing you let go of without saying goodbye?

I was going through old claim files yesterday—routine stuff, mostly. Then I found one from a woman who’d lost her husband in a fire. She didn’t want compensation, just asked that the insurance company send a photo of the house after it was rebuilt. Said she wanted to know what remained. I never sent it. Never even wrote back. I kept thinking about how much she must’ve needed that small proof of continuity. And now I wonder: what small thing did I leave unfinished? What quiet farewell did I forget to make?