I do aikido, a Japanese martial art whose most obvious distinction among martial arts may be that we're falling down all the time. We take turns practicing the techniques on each other, and depending on circumstances, we often hit the mat with a fair amount of force. On top of that, accidents happen, or we don't get out of the way fast enough, and periodically we get hit (to draw from my experience) in the head, or the nose, or in the middle of a leg muscle. People wince when they see or hear about this, and it's hard not to, right? All this talk about getting hit in the head or falling on the floor. That hurts, doesn't it? Pain is bad. We hate pain. Typically I explain to people that "you get used to it". Which is true, but not complete: what changed that I'm no longer bothered by the impact of falling onto my side from three feet above the ground, especially if I get to hit the mat with my hand first? There's still a little sting there. I'm also not particularly bothered by shots to the head or nose, or any number of other things. Why?
The reality is that when we get hit, most of our pain is mental. You can watch this happen visibly in slow motion with kids: at canefighting in November, the teacher's seven-year old got bopped gently on top of the head. He stopped, stunned, for a few seconds, looked confused, and then eventually decided that his head hurt and this was a problem. In Buddhist practice we call this the "second arrow": Eziekel got hit in the head, and that was the first arrow, and unavoidable. But then he added a second arrow, by deciding it was a problem and being upset about it. We do this all the time, adding our own mental anguish onto whatever's really going on.
So in aikido, we learn two things that help with the bumps and falls:
I'm not sure. It's mental training: learning to have some perspective on things like getting punched in the ribs.