Well. Note the use of the verb "attempted."
I got about 20 minutes in, not always following all the moves but doing a reasonable job of at least keeping moving and kind of faking it. And then I did something too fast, or zigged when I should have zagged, and suddenly I couldn't catch my breath. Between the adrenaline from the workout and the now gasping for breath, I started panicking, and then I started feeling on-the-edge of hysterics. It felt almost exclusively physical, the hysteria, rather than emotional, if that makes sense? If I hadn't been having trouble breathing, I probably could have channeled the adrenaline into energy. If I hadn't had the adrenaline in my system, I probably could have calmed down my breathing. Between the two, though, I was screwed.
So, not wanting to disrupt the class, I toughed it out to the end of the song, which was fortunately only maybe another 30 seconds or so, and when everyone broke to the walls to grab their water bottles, I grabbed mine and headed out of the class.
I got back to the locker area, plunked myself down in one of the curtained changing rooms, did deep breathing and relaxation until I felt calmer, drank some more water to loosen up the knot in my throat, and came home and had a beer.
I think that I'll avoid the classes for a while; I'm just not up to them yet.