His return to golf comes shortly after he watched Tiger Woods win the Masters, which apparently triggered something in him.
"Sometimes you've got to take a step back and realize what you had," Peterson told 104.5 ESPN Baton Rouge. "I was in an office for seven months and it was fine when I started, I was paying the bills."
"Then the Masters came along and I'm watching this kid Patrick Cantlay," Peterson continued. "In 2011, (Cantlay) finished second to me in the national championship when he was at UCLA, and he's finishing ninth at the Masters. I beat him a lot and I'm just like 'Man, that could be me.'"
Peterson knew it was time to return to the sport when he witnessed Tiger put on the green jacket for the fifth time.
"And then Tiger wins, with his story, it was just so inspiring, honestly. And I quit my job, seriously, the next day after the Masters," he said.
Peterson left golf last year after failing to secure status on the Web.com Tour. He played in 12 pro events in 2018, nine of which were on the PGA Tour, thanks to a major medical extension.
He returns with no status on either North American tour, which means he will have to work his way back through Monday qualifiers.
"I'm taking a big risk, and I really don't have any place to play right now 100 percent, so I have to qualify and stuff," Peterson said. "I will get back. I know I will. It's just kind of a regret watching the guys that I played with my whole life finish top-10 in the majors and just knowing I can do it."