I feel like I want to explode and bounce around the room, or scream and sing "la la la la la la" at the top of my lungs - not that I can remember actually ever doing anything like that, even though I've felt those desire many times before. Instead, everything is locked down tight, even more restrained than usual. It's not something I do consciously; I've done it since I was a kid. I vaguely recall being slightly hyper when I was 2 1/2 or 3 - but after that, never. I only realized at age 14 or 15 that I clamped down on my physical movement when I get like this, and only a few years ago noticed that I did the same thing to my emotional state, too. I become more emotionally vulnerable when this happens, and I socially retreat from most interaction; I'm absorbing as much input as possible from every source I can, and can key in on the smallest of things. The overload swamps me. I feel drained.
Where does all this pent-up energy go? My mind races more than usual, and it's even more difficult to keep focus on any one thing. Sometimes I end up spewing all sorts of vaguely coherent prattle. I tend to make very broad (and sometimes bizarre) associations between things anyway, but when I get like this and the churn goes way up my chain of thought goes even wilder and wanders all over the map. It's usually considered socially unacceptable to flail about with hyperactivity, but blathering wildly is usually just fine. Even if it means that I become obsessive-compulsive over tiny things, and get waves of panic from being unable to deal with all that's going around me, and I act a little odder than usual - they don't really show, and so I don't make a spectacle of myself.