Conor McGregor revealed he lost his motivation for UFC after achieving a rapid rise to prominence in mixed martial arts, but he says he has now rediscovered his love for the octagon.

McGregor returned after a 15-month absence on Saturday, claiming a rapid first-round victory over Donald 'Cowboy' Cerrone in Las Vegas, which took just 40 seconds.

The 31-year-old had not fought since losing to Khabib Nurmagomedov in 2018, while the Irishman had also ventured into boxing when he faced Floyd Mayweather Jr in 2017.

His time away from mixed martial arts started with a six-month ban imposed after a post-fight brawl outside the cage following his showdown with Khabib.

McGregor was then arrested and charged with strong-armed robbery and criminal mischief in March 2019 after it was alleged he took a man's phone and smashed it on the ground in Miami – the charges were later dropped. In November last year, he was fined €1,000 after pleading guilty to an assault of a man at a pub in Dublin.

However, McGregor insists he is now fully focused on his mixed martial arts career, after acknowledging that he let the people who supported him down.

"I achieved it all. I broke the game before I was 30 years of age, simple as," McGregor told a news conference. "One belt became not enough.

"My coach says it’s the worst nightmare for a coach if his student achieves it all – the money, the fame, the belts, all of this. What then to motivate me?

"I probably had to go through that and then come back to it for the love of it, which is why I got into it in the first place. Everything's a learning curve, you learn what's right and wrong.

"I wasn't committed and it was a disrespect of the people that believed in me. People were taking the time away from their families to come and help me and I wasn't committed with it. I would train and then I'd go missing for three days and then I'd come back and it was sporadic and on my call."

McGregor is adamant the only trick to success is hard work and discipline.

"It's all about commitment and then just do what you need to do. All I did was put in the work," he added.

"We know what the work is we need to do but sometimes you just don't do it. It's like little defeats and then those add up and your interest wanes, then you can get injured and all those things.

"It's about commitment, that's it. You put in the work and you reap the rewards, there's no secret sauce to this. Recognise what you need to do, f****** do it, and you will succeed."