I was standing in partner dance class when this man -- who tends to dominate space -- approaches me and I sense he's going to steal the space from under my feet. He hits me with a body check that would have moved me three feet, instead I prepare and he bounces off. He acts like a confused victim, puts his shoulder against me again. I say, "Get your fucking hands off of me." He complied, more confused-victim act.

The thing is, this happened in about two seconds and I didn't actually "decide" to do any of it. It all just came out of me, like I was a spectator, it was actually very strange. Do I need to be concerned about myself here or is this just how these things work?

As an aside, I've noticed a huge frame-shift from lifting/training over the past 1.5 years; I stick with my gut more. Before, I would have been, OK here you go.