The old leash can carry memories of walks nobody considered important enough to record.

Ordinary repetition leaves almost no record. Thousands of walks happened and none were photographed, because they were background rather than event, and the only thing holding them now is a worn strap in a cupboard. Objects end up being the archive for everything too routine to write down. That is why a plain item can be so heavy to pick up.

If you have something like that, there is no schedule for keeping it or letting it go. It may help to write down one walk: the route, the weather, what they always did at the corner. A written record makes the memory less dependent on the object.