For Anthony Pettis, fighting serves as a metaphor for life. You get knocked down, you get back up.

“I lost my dad at a young age,” the UFC lightweight notes of his father’s death by a knife-wielding robber in 2003. “I was faced with adversity at a young, young age. I had to get through that. At 16-years old, you’re figuring out what kind of man you’re going to be, what you’re going to do in your life. I got through that on my own.

“Then I found fighting. The same exact thing happens. You lose in a fight, you have to come back ten times stronger and figure out what went wrong. So much stuff you have to deal with on your own. There’s no team involved. There’s no blaming somebody else. It’s based on you.”

Instead of staying down, Pettis rose from that low point. He immersed himself in training to eventually become the UFC’s lightweight champion. He opened up a sports bar, a barbershop, gyms, and a cell-phone store in his native Milwaukee. He even appeared on a Wheaties box.

Just as life knocked Anthony Pettis down, so did his sport. Last year, Showtime lost the lightweight championship to Rafael Dos Anjos. Just as he did when the world cruelly floored him in his teens, Pettis brushes himself off and fights on against Eddie Alvarez this Sunday in Boston.

At 18-3, Pettis owns wins over Benson Henderson, Cowboy Cerrone, and Gilbert Melendez. But the 26-4 Alvarez, Puerto Rican (in part) like his opponent, enters the octagon as stiff competition boasting victories over Gilbert Melendez, Pitbull Freire, and Michael Chandler. After overcoming adversity, Pettis must surmount another obstacle to travel closer to where he seeks to go in life.

Fans cheer for Anthony Pettis because he fights as perhaps the closest thing to a human highlight-reel in mixed-martial arts. The head kick to Benson Henderson after using the side of the cage as a springboard, and the jaw-dropping, man-dropping kicks against Joe Lauzon and Danny Castillo, show that Pettis knows how to finish a fight with an exclamation point. But fans also cheer for Pettis because he competes as an aspirational fighter. Everyone wants to come back against what life hands them. Pettis shows them they can. We like a fighter who’s a fighter.

Whether it’s business, athletic competition, or life, he figures success comes through “trial and error.”

“If I put in the time and work,” the former WEC and UFC lightweight champion says of his businesses, “I get the success. If I don’t, then I get the failure—same thing with my fights, same thing with life.”

Everyone watching Sunday night’s fight on Fox Sports 1 shares something in common with Anthony Pettis. They all fell down. Not all of them stood back up. That’s what separates great fighters from good ones in the ring and differentiates successes from failures outside of it.

As he did almost thirteen years ago, Pettis looks to rebound after a loss. Should he again adapt and overcome, the applause responds to something surely worth cheering.