This reminds me of an experience I had when I was in the middle of my 1800 mile adventure.
I'm somewhere in the middle of my adventure, and like Tipi said, it's like a forced march. But I don't know if it's so much for the reasons he mentioned as for my hunger. I was always starving. I felt like I was trying to out-run my starvation all the time. It's like a vicious cycle, too, because the bigger mile days you do the hungrier you get so you race your hunger even faster with bigger mile days. Yes, I dreamed of restaurant meals all the time, but not really hotel rooms. I just wanted to eat.
So here I am and this guy sees me and he's so excited he just wants to talk shop. Talk gear, mostly. He was so excited about his gear. I'd been out there long enough by now I never even thought about my gear anymore. My gear was just gear. Just a tool. Gear talk was so boring. I wasn't very nice to him. I was curt and I hiked away as quickly as I could. Why? Because the Timberline Lodge was only 5 miles away and I'd been dreaming about their buffets for many miles and I was so very hungry and had eaten pretty much all my food.
Later I saw him again and being more well-fed I apologized for being so curt.
I would have enjoyed hiking with him for a while. I was very lonely. But I was so much faster than him now. I was in this space of having never been particularly athletic, plus being in my mid-40s, here I was doing this incredible physical thing I had no idea I could do. I was loving that part of the adventure. I stood on the balcony of the Timberline lodge and looked at Mt. Jefferson way out in the haze and it boggled my mind that I had been standing there only yesterday. How had this old fat lady walked so far? I really liked that part of my adventure. I didn't want to slow down. I wanted to see if I could do even more.
This approach does have its disadvantages, though. The missed side trails definitely being one, and the missed beauty with your mind preoccupied by your feet and your stomach for another. I wouldn't necessarily disparage thru-hikers for giving in to this experience. You may never get another chance in your life to truly test your own physical power.