If you’ve never seen Joanna Jedrzejczyk fight before, let me just say this: It is a marvel.

Not just because of her striking, which is so crisp and precise and thrown with such ferocity that you’re often left wondering how her appendages stay attached to her body (earlier in her UFC career, Jedrzejczyk actually broke her right hand mid-fight on two separate occasions), but because of her stubborn persistence. She is the Rafael Nadal or Russell Westbrook of her sport—the harder a fight gets, the more cornered and unpredictable Joanna becomes. When you think she’s about to throw a punch, she catches you with an elbow. When you’re anticipating an elbow, she sends a front kick your way. When you’ve got her right where you want her, primed and ready for the kill, she suddenly becomes the predator.

“There are so many talented fighters. And then there are fighters who must work like butchers. They are champions because they work hard every day. I believe I have a little bit of talent, because I learn very quickly, but I’m like the butcher. I must work my ass off every day. I had to work my way to the championship, and I still must work to defend the title.”

The 30-year-old Jedrzejczyk was born amidst the Revolutions of 1989, into a post-Communist Poland—“a great time in Poland,” she recalled over coffee when we met up in Fort Lauderdale. Her parents owned a small grocery store and would wake up at two o’clock in the morning every day to prep their shelves with fresh meats and produce. Sometimes they would work 20 hours a day. During Christmas, Joanna would dress up as a tiny Santa Claus and pass out sweets to the customers.

“My parents were like, ‘You’re insane, you know?’ But I like to be around people.”

If she wasn’t at the store, helping her parents where she could, Jedrzejczyk could almost certainly be found running around the streets of Olsztyn, playing soccer or Palant. (Think stickball.) There were often teenage passersby who would heckle little Joanna and company. And while her companions may have been intimidated, Jedrzejczyk was often the first to talk shit right back.

“They used to call at us, like, ‘Hey, kids!’ And I would stand my ground and say, ‘Who is a kid? What are you going to do to me?’ I always stand for my people. You can put a hundred people in front of me. If I don’t accept what they’re saying, I’m going to stand my ground. Even if there is a war coming, you know? But if I’m wrong, I will be back and standing in front of those same people and say, ‘Hey, I was wrong. You were right.’”

By the time she was a teenager herself, Jedrzejczyk decided to give taekwondo classes a shot. A few years earlier she dealt with some unexpected liver issues and had put on a little extra weight. Taekwondo seemed like a great way to get back in shape, but Jedrzejczyk quickly became bored. Instead, she side-stepped over to Muay Thai, a more punishing physical discipline, “and from the first class I fell in love.”

"There are so many talented fighters. And then there are fighters who must work like butchers. They are champions because they work hard every day. I believe I have a little bit of talent, because I learn very quickly, but I’m like the butcher."

Jedrzejczyk couldn’t get enough of the training. The rush of pushing herself through a session followed by the extreme exhaustion became almost like a drug. Every day she vowed to outwork the version of herself from the day before. Even after Jedrzejczyk found out that one of her coaches was pocketing money from students and left the gym she had called home for two years, she couldn’t be deterred. She set up shop in her parent’s garage, dissecting videos of other Muay Thai fighters and shadow boxing in four layers of clothing to stay warm during the Polish winter.

“I said to myself, ‘Are you fucking crazy? You are 18 years old. You should go out and get a car! You can drink, you can party, you can go to the clubs!’ But I was not about that. I felt like I had a mission. Like I have to do something.”