We know our attention is fully on a task, when everything in our peripheral vision has faded away. We know our attention is fully on the task, when we have forgotten the headache after a couple of hours later.
We know our attention is fully on the task, when we feel a satisfaction while working on the task. We know we’re truly focus on the task, when we feel in sync with our mind and body.
We know our attention is on the task, when nothing else seems to matter and that time seems to stop. We know our undivided attention is on a task, when we have experienced briefly eternity to just be reminded that we’re finite beings but still alive.