RULE NUMBER ONE for the woman who gets a black eye during karate class: Do not change your clothes before going to the emergency room. Go in your uniform. Go covered in sweat. Otherwise, you will spend a lot of time answering questions about your relationship history. You may be suddenly confronted with a social worker, or even a policewoman, who will sit down next to you and be very reassuring. And it will take forever before somebody actually examines your retina, which is what you came in for.

RULE NUMBER TWO: Expect to spend a lot of time answering questions anyway. “Why would a woman like you want do a thing like that?” asked the doctor when I had explained why my cheek was numb and I was spitting out blood. This was not my first sparring-related ER visit, and I knew the drill. I wore my gi pants and a wringing-wet “Fight Like A Girl” T-shirt, and had my black belt slung over one shoulder, so the doctor wasn’t worried about my relationship history. He just thought I was nuts.

Now, this man weighed well over three-hundred pounds, and barely fit in the exam room with me. So I decided not to give the easy answer: “Fitness benefits.” I wasn’t about to insult the only person standing between me and a lifetime of monocular vision. OK, technically, he wasn’t standing. He conducted the exam from his little wheeled chair, which was barely visible beneath his bulk and thus gave the impression that he was hovering eighteen inches off the floor.

Without fitness as my excuse, I was stumped. Why would a woman like me want to do a thing like that? First of all, I wasn’t sure just what “a thing like that” was. I had told the doctor I’d been sparring; what did he think that entailed? Mud wrestling? Bald guys named Snake slamming each other’s heads into the ground and spitting out teeth? And I wasn’t sure what “a woman like me” meant, either. Like me how, exactly? White? Straight? Free of tattoos? How is a woman who wants to do “a thing like that” supposed to look? And perhaps most puzzling of all, why is a man who weighs twice what he ought to questioning my lifestyle choices?

“It’s fun,” I said at last, and shrugged, and swallowed a little more blood.

I was telling the truth, but in fact it’s more complicated. Head trauma definitely isn’t fun. Head trauma sucks and, short of actual brain damage, eye injuries are the worst kind. The standard advice to “go for the eyes” in a self-defense situation is worth remembering. Even if you do no real damage, your opponent will hesitate at least briefly, wondering if his eye is still intact, in its socket where it belongs, and working. I learned this firsthand when I got stabbed in the eye with a rubber knife: There is no fight so intense that you cannot be momentarily halted by the thought of yourself in an eyepatch.

Karate, now—that is fun. But it also requires a lot of discipline—more than I really possess, to be perfectly honest. I’m a pretty half-assed black belt. If I were good, I wouldn’t get hit in the head so much. My one real talent is my ability to absorb damage. I can take a punch, even though I’d rather not, and perhaps this is what makes me so bad at getting out of the way. Still, karate provides a structure that lets me fight without seriously hurting someone—or getting seriously hurt myself, or arrested. So far. And that has been fun.

The ER doctor, clearly unimpressed with “fun” as a reason for getting a black eye, moved on to more pertinent questions: Had I lost consciousness? No, luckily. Did I remember what happened? Yes, it was all still quite vivid, thank you, especially the crunching noise from just below my eye socket, and back behind my nose. Breaking bone has a unique sound, and when it’s happening inside your own skull, it takes on a truly memorable resonance. I can still hear it, right now, if I try. No memory problems there. I also remember that it hurt, a lot and immediately.

The doctor rolled around the exam table, found his ophthalmoscope, and wheeled back over. He stood briefly to peer into my eye, said it was fine, and collapsed again, apparently exhausted. In the midst of my relief, it occurred to me that, sitting where he was, his head was within easy striking range of my right foot. Despite what you see in the movies, kicks to the head are virtually impossible to land in real life, so I was intrigued. Propped up on his little stool, the ER doctor was an obese sitting duck. I found myself wondering about the physics of kicking a seriously overweight person. A rising front kick under the chin would lift a seated man of average size a few inches up off his chair, I figured. I’ve never fought anyone much over two-hundred pounds, though, and I wondered what the effect of the extra weight would be. Certainly there would be more resistance when his head snapped back. Could you actually decapitate an obese person with a kick, I wondered? How much easier would it be than decapitating a normal-sized person?

Don’t get me wrong; I had nothing against the man. That he was large, and full of doubts about me, was neither here nor there. Target observations are just part of the background noise of my mind. The woman who puts her hand on my shoulder as she squeezes past me in a crowded conference room: how many of her fingers could I break? The guy standing a little too close behind me in the elevator: back fist to the face, or elbow strike to the solar plexus? It’s nothing personal. It’s just hard to turn off, that’s all.

I averted my gaze from the doctor’s chins and asked about the blood trickling down the back of my throat. Sparring gear had protected my eye; the fist that hit me was well padded. But I took a pretty stiff punch nonetheless. A few minutes after the round, I noticed that my throat felt odd, and when I saw the blood I suspected the impact must have torn my sinuses loose from whatever one’s sinuses are moored to, and shifted them backwards a few millimeters.

“Could be,” the doctor commented when I related this theory. He flashed a light around the back of my throat in a desultory fashion, like a man checking a drain for rats. He didn’t seem to think it was a big deal. I decided he was right. My sinuses have always been a mess. I fell off a lot of horses as a kid, and landed on my face as often as not. What’s a little more damage, really? Until my sinuses actually start to emerge from the back of my skull, there’s probably nothing to get excited about.

I was feeling pretty good now; no eye problems, no concussion, and no reason to worry about the blood. Then the doctor explained the numbness in my cheek. It was most likely nerve damage, he said, common with fractures around the eye socket. It should resolve on its own, but it could take up to a year. Part of me found this interesting (Nerve damage, hmm, that’s a new one_); part of me was seriously freaked out (_To my face? My FACE?). But the rest of his advice was routine. Take some Tylenol for the pain: Check. Ice it: Check. See your regular doctor for follow-up: Check. (My regular doctor moonlights as the physician for a minor league hockey team. I could walk into his office carrying my sinuses in a Ziploc bag and he wouldn’t bat an eye.) This was familiar ground for me, and oddly comforting. All in all, it was a pretty typical ER visit, apart from the super-sized doctor. What happened afterward was pretty typical too: That night, when my family was asleep, I sat up in bed and cried.

Oh yes, cried like a baby. RULE NUMBER THREE for the woman who gets a black eye in karate class: You will cry. I don’t know if guys do this (if they do, I doubt they admit it), but every woman I’ve talked to who has suffered a head injury has, at some point, cried. Maybe not when it happens—too much adrenaline—but afterwards, when the shock starts to wear off. Because the terrifying thing about a head injury is that you can’t see it. You can feel it, maybe observe it in the mirror, but you can’t separate yourself from it the way you can from a broken toe or a bum knee. You can’t say, There’s the injury, because the injury is here. Whatever it is that you are, it’s all housed up here, and when you screw around with it, you run the risk of not being you anymore. Head trauma is not just a bad boo-boo; it’s an existential threat.

So the doctor had a good question, and it’s hard not to ponder at 2 a.m. when you are sobbing into an icepack: Why do I do this?

I started fighting because of my gender, not in spite of it. I took up karate, and later self-defense instruction, because women are so often the targets of violence. No, I don’t enjoy answering questions from concerned nurses and social workers, but I sure as hell understand why they ask those questions. I have friends, from childhood on, whose lives were irrevocably changed by violence against them, their mothers, or their daughters. My training began with a simple, blind need to fight back.

Also, let’s face it, I have a rotten temper. The urge to fight comes naturally to me. Not the urge to compete—competition involves rules and standards, and I fail to see the point of all that if something really important is at stake. Rip their balls off, I say, or just stay home. With that attitude, what hobbies am I likely to enjoy that don’t involve injury?

And even injury has its benefits. For example, it’s tempting to think you understand violence because you’ve seen it on television. You don’t. You can’t experience violence from the outside, or through a screen. You have to feel it: the sharp pains and the dull ones, the unreal feeling of intimately familiar body parts knocked askew, broken, damaged, changed. Injury locates us more definitively in our bodies than almost any other experience; it confronts us with our own vulnerability. When we heal, what has changed about us? Are we the same again, ever? By getting hurt, I’ve learned a lot about myself, my mortality, and the things I consider worth fighting for. Most importantly, being injured has taught me that there are worse things than being injured.

There is a common perception that women can’t fight, or won’t fight—at any rate, that we don’t fight. That perception is one reason we are targets of violence, and I fight in part to prove that perception wrong. But I also dislike the perception that women only fight because we have to, that it’s an unnatural, unfeminine behavior we’re forced into, to protect ourselves from all the big bad violent men. The truth is, some of us fight because we like to. Even if we’re bad at it. It’s just fun.

RULE NUMBER FOUR for the woman who gets a black eye in karate class: Next time, keep your goddamned guard up. You want to get killed?