Day 15: What's happening?

First day of my third week! I get right to it when I get home from work. This is my third time through the Core Synergistics workout, but there's an exercise that I don't think I've brought up yet that I keep meaning to: The Prison Cell Push-Up. Now, a couple of weeks ago, I mentioned that I hate the Dreya Roll. I was wrong (those actually aren't as awkward as they were when I first started, and I've improved on those quite a bit). I hate the Prison Cell Push-Up. In these things, you do a push up, then bring your right knee to your chest, then do another push up, then bring your left knee to your chest, then do another push up, then jump up to a standing push up, then do it all over again. Tony says to do it as fast as you can. I can't do them very fast, in fact, I can barely make it through, like, two of those lousy things... After that, I'm kind of stumbling my way through one and a halfish more, then, I'm a pile of jello. Prison Cell Push-Ups suck. Yep.
Anyway, I make it through the rest of the regular workout. I really push myself today, so I'm at the point of exhaustion. Although I did the bonus round last week (sort of), I decide that I'm just too spent to do it today... but then all of a sudden, I find myself struggling through the bonus round anyway... What's going on here? What's happening to me? Have I become some kind of P90X drone?