Whatever the reason, I just didn't have "it" today. I felt all right physically, yet I couldn't shake the feeling that I wasn't operating at 100%. I'd say that this realization kicked in shortly after arriving at work and learning of a mistake I made, but I may have woken up with it. (Or without it, as it were.) I'm not sure.
Chalk it up to not enough sleep, not enough to eat, or something else. It doesn't matter. I was lacking.
I tried working out, but my legs weren't there. Neither was the mental stamina. Halfway through I threw in the towel. This is the first time I've done that nearly two months into this regimen.
I really hope it returns tomorrow.