Nick Newell didn’t do a thing for about three months after he retired.

“I just rested,” the former World Series of Fighting lightweight standout said. “I did nothing, just let my body heal. Didn’t set foot in a gym or anything.”

From there, the Connecticut native hit the ground running. Newell retired at age 29 toward the end of 2015 with a 13-1 record in part because of nagging injuries that seemed to keep him from performing at his best, and in part because he wanted to get the rest of his life in order.

Now he’s back. Legacy Fighting Alliance announced Monday that Newell will come out of retirement and compete under its banner, and in his first interview since, Newell explained to MMA Fighting what he’s been up to and why he’s returning now.

“At the end of the day, I missed it,” Newell said. “I’m a competitive person, I enjoy the competition, it’s something that you can’t quite describe unless you’ve done it. But I wanted to make sure I was doing it for the right reasons and now it feels right.”

During his meteoric rise through the sport — Newell garnered attention earlier than most due to his condition as a congenital amputee, as his left arm ends just below the elbow — he found himself caught up in the gears of the sport’s never-ending assembly line.

“I was never able to think about my future,” Newell said. “I never had time. I got my college degree, the fighting thing took off, and one thing happened after another. I bought a condo and it was just, it’s not like I was making millions of dollars right? I had to fight three times a year just to be able to pay my bills.

“I started thinking about my future, and meanwhile, my back goes out, my neck’s injured, I tore my MCL,” Newell continued. “I’ve never been one to half-ass anything. I didn’t want to be one of those guys left with nothing. I needed to take a second to breathe and to think about my life after fighting.”

In April 2016, Newell opened his gym in West Haven, Conn., an affiliate of the Fighting Arts Academy of Springfield, Mass. He teaches everything from pro MMA classes to youth fitness classes. One of his fighters, middleweight Justin Sumter, walked into his gym with an 0-1 pro record and is now 4-1 and a regular in the CES promotion.

“Getting the gym up and running and thriving helped me get back to the right place,” Newell said. “I don’t have to fight for money now. I don’t have to worry about whether my bills will get paid. I can do this for my legacy, and I can do this because I love to compete.”

Newell is targeting early 2018 for his return bout. He’s getting married in November and going on a honeymoon from there, and he’s not going to make like Jeremy Stephens and postpone it.

“My fiancee’s been with me since before she even knew what MMA was,” Newell said. “I’m training all the time, so it’s not like I’m out of shape, but we’re going to have our wedding, the honeymoon, the holidays, then I’ll hit the ground running with the New Year and I hope to fight soon thereafter.”

For all Newell has accomplished — and he retired on a two-fight win streak — the bout he’s heard most about was the one he lost: A second-round TKO to then-WSOF lightweight champion Justin Gaethje at WSOF 11 in 2014.

“That’s the one everyone comes up to me and talks about,” Newell said. “That’s how it is, 13-1 and they ask about the one.”

Gaethje’s gone on to big things — after running through WSOF, he went to the UFC, where his debut win over Michael Johnson in July is considered by many the frontrunner for 2017 Fight of the Year — but Newell doesn’t hate.

“I can’t resent him,” Newell said. “It was his day. I definitely had my moments in the fight, but I’m at my best when I can impose my wrestling and I wasn’t able to. Justin’s a respectful guy and he represents the sport well, so I’m happy for his success.”

And Newell holds out hope that one day, the door will open to him, as well. The UFC’s previous ownership was wary of bringing on a fighter with Newell’s condition. While no one’s said anything explicitly to the contrary, he hopes new ownership will have a different attitude.

“I mean, the UFC isn’t going to bring on someone who’s been retired for two years,” Newell said. “But the world’s changing. I know I’m one of the best fighters in the world. I know I could go in there and beat half the guys in the division now. I feel great, as good as I’ve ever felt. I’m just going to go out there and prove myself all over again, and this time, make it so there’s no doubt I belong.”