Josh just said this recently about "losing it" while dancing:
"It seems possible to me that the preference for losing it might sit very nicely with the habits of a listener who scrutinizes music a great deal, and routinely makes fine distinctions about music, and perceives closely what's going on in it. When you lose it, maybe you can stop noticing things like these, and, importantly, feeling constrained by them."
It's probably true for a lot of people; in my own case, I tend to find myself hyper-aware of musical detail while I'm "losing it" - in fact the two exist in a cause-and-effect relationship of uncertain direction. I think it's a case of physical immersion. It's actually quite possible, I believe, to physically immerse yourself while listening to music in your chair at a computer, for example. In that environment I find myself sensing how my body
would be responding if I gave it the unfettered right to. When I'm actually dancing, being able to actually see/feel my body's responses gives me a much more immediate and powerful insight into how the music actually works from a dancing perspective... but it is at the same time
too much information; your mind can only hold so much. It's like holding a photograph up to your nose and trying to grasp the big picture, but only being able to discern, in perfect detail, the tiniest portion. My mind while I'm dancing is a running commentary of enthusiastic observations with no narrative, so random in fact that it approaches incoherence. This is, I think, the heart of "losing it" on the dancefloor: the condition of not being able to establish a position, because the music and your body never allow you the chance to step back, gain perspective, pass judgment. It's a great feeling.
P.S. No time to rave about it now, but I'll note quickly that it is a matter of urgency that you all go out and procure Sean Paul's
Dutty Rock - an absolutely amazing piece of work, and frequently a helpful tool for testing the evidence of the statements above.