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

I was going through old claim folders yesterday—some from before I retired—and found a file where the client had written 'thank you' in pencil on the back cover, but no name. Just that. I sat with it for a long time, wondering if they ever got what they needed, or if the thank-you was for something else entirely. Now I keep thinking about all the things we don’t finish, the quiet exits. What’s the last thing you let go of without saying goodbye? Not a person, not even a moment—but something small, that still hums.