At the gym there's a row of people exercising on treadmills looking straight ahead at TVs on the wall. So if I go to work and look through the glass at them, I see everybody moving but I see no one going anywhere.
I have a friend who worked for three years setting up his own consulting firm. I know he put in tons of hours and worked on the phone back to back every day. He built his whole life based on what he was able to produce until his back went out on him. He used to tell me how he'd lie on the floor in between phone calls because he couldn't sit anymore and he'd put his laptop on top of a pile of books to work while lying down. He never stopped. He just kept making the machine adjust until he could no longer make the machine adjust.
We generally don't think of it this way but your body has its own way of keeping track of things. The way in which your body keeps track of what's happened to you over a week and what has contributed to you being unproductive and being productive is no different. Sleep debt is a debt no matter how you acquired it, if you acquired your sleep debt because you worry or you created your sleep debt because of your ambition. And your back doesn't differentiate why you have been bending over all day, it just knows how long you've done it, and it sends you a bill, figuratively speaking.
When everything is working well or normally for you, there is a totally different feeling in your relationship with those three distinct activities, walking across the office to get coffee, standing in line at Starbucks, carrying a bag of groceries up a flight of stairs, as opposed to all those three distinct activities when they are out of order. Until you either lose the ability to perform those three activities or you say to yourself, why do these three activities seem so hard for me to do, you will not fully appreciate how much easier those three tasks were for you to accomplish when your body was functioning properly.