Strange lack of body awareness

The other day I went for a hike, at a trail that I often use. It's hilly, public trail out on a ranch near town. Mountain bikers use it, too. I've done this trail about 10 or 12 times total probably. The first time, when I went with family, it probably took the whole group of us 2 hours or more to get around the whole thing. My fitbit rates it at about 10,000 steps and about 32 flights of stairs worth. So, it's a good, challenging workout for me at this point in my fitness.

One of the last times I went, though, I had the odd sensation that it was just OH SO MUCH HARDER than usual. It was warm out, sure, in the 80s, but not any warmer than the last time I had done the trail. Was it the week I had had previously, I wondered? Or because I was listening to an audiobook on my ipod that I had already heard before, rather than one of my nursing school lectures that I really had to concentrate on....yes, perhaps it was distraction that was key? Or maybe I hadn't slept as well or as long the night before? I even started wondering if maybe I had accidentally taken the 'long loop' instead of the 'short loop'.

It was only when I got to the end, back in my car, and peeked at my clock that I realized why. I had gone around about 20 minutes faster than the last time I did it, without even realizing it.