A lost-and-found desk collects separations without knowing which ones will become reunions.

A collection of lost things is a collection of separations whose endings are unknown. Some will be reclaimed with relief, most will never be, and the desk holds them all identically because it cannot tell which are missed. Loss looks the same from outside regardless of what it costs.

The part you can act on is the reclaiming. Go back for the thing you assumed was gone; the rate at which lost objects are still sitting where you left them is higher than people expect. And the same applies to lapsed friendships, which are frequently not lost but simply unclaimed.