You can lose the reason an object mattered before you lose the reluctance to discard it.

The reluctance outlasts the reason. You keep the object because putting it in a bin feels wrong, and if pressed you could not now say what it commemorates, only that it commemorates. Feeling is a more durable storage medium than explanation, which is why houses fill with things whose significance has quietly evaporated.

Pick up one such item and ask what would be lost if it went. If nothing specific comes, you can photograph it and let it go, and the resistance usually turns out to be smaller than expected. Where something real does come back, write it down and put the note with the object.