There's a night shift you never supervise. The cut on your knuckle from Tuesday has closed over by Friday and you couldn't say when. Bone knits. The lining of your stomach replaces itself every few days without consulting you.
None of it waits for your motivation to show up.
On a day when you've done nothing you'd count as healthy, that machinery is still running at full effort on your behalf. You're not starting from zero tomorrow. You're adding to work already well underway.