The 62-year-old legendary fighter insisted he is a very different person to the man he was at the height of his ring success and looking back is hard because of his behaviour at the time.
Asked how he felt about being inducted into the International Boxing Hall of Fame, he told Boxing News magazine: “You want the truth? I’m not that man no more, a lot of it is linked to my past.
“The parties, the drugs, the women, and all things like that – now that I’m a Christian man, it’s put a dampener on it.
“Thank god I achieved it, and all that, but there’s always a dark cloud over it.
“What I’ve achieved is beyond my wildest dreams. But I look at it through how much pain I caused my wife [Carolyne] throughout my career.
“If I was a goody two shoes, living the life, I’d be so over the moon,.
“But whenever I talk about boxing, there’s always something that’s connected ot it.
“World titles, great – that’s a good side of it, a brilliant side of it.”
But despite his many regrets, Nigel is unsure if he’d have been the same fighter if his life had panned out differently.
Asked what he might have done differently, he said: “I’d love to have been faithful to my wife. That would mean more to me than anything else.
“A lot of the things I went though in my career was negativity and depression and bipolar.
“There’s a lot of things I’d love to change, but, if I’d changed, would I have been the same person in the ring?
“When trainers used to tell me things, it went in one ear and out the other – I was just a fighter.
“I just done what I wanted to do.
“When I watch how my son [Conor] boxes, he really listens to Tony [Sims]; I was never that way.”