Perhaps this is the secret of each visible flow: the movement disappears alone, but the contact leaves a trace. What we remember is not the transition, but the moment when something surrenders, echoes or changes. In the end, it is not the water that passes, it is the trace that remains.
We don't recall the transition; we remember the instant when something gives up, echoes, or changes. The water that flows is not what stays; it is the trace that stays.