The Leicester fighter, 32, quit the ring after his sixth-round TKO defeat to Scott Quigg back in November. But he will fight in his home town on May 9 with his opponent still to be confirmed.
He cited weight problems and lack of motivation as reasons to retire at the time, though he also admits that being unable to go back to his former job as a binman is also a factor.
"I know I can still be a world champion," he told the Leicester Mercury. "I've been sparring and it's definitely still there. I won't say I feel better than I used to, but I'm enjoying the training more.
"I'm still eating healthily and now I'm eating more. I had been making 8st 10lbs for a long time and I don't think keeping my weight down for all those years did me any good.
"I walk around at 10 stones these days - and that's a lot of weight to lose for a fight.
"I had got fed up with the way I was being treated as well. I had worked hard, proved I was good enough to fight at world level and ended up fighting at domestic level again. I struggled to get up for my last fight."
Monroe says another reason for resuming his boxing career is that he has not been able to get his old job as a binman back.
"If they had me back on the bins, I wouldn't be thinking about boxing again," said Munroe.
"It was the perfect job for me. I was outside, exercising, seeing people and enjoying myself. I was there for eight years and only had one day off sick when they sent me home.
"We worked as a team. I was never disrespectful, did my work well and never had any disciplinary problems. I always said I would go back on the bins when I stopped boxing.
"I've been told they won't have me back because I've got an attitude problem - and that's rubbish."