I’ve definitely changed as a person because of professional boxing,” George Groves says on a rainy morning in Chiswick as, over breakfast, he shows the bruising honesty of a fighter who has tasted fleeting glory while being hurt in and outside the ring. Groves looks up from his scrambled eggs and mushrooms and explains how boxing has marked him.

“I’m now paranoid and cynical. If there is a change in the situation I will assess it and usually come up with the negative. It’s very rare I see something genuine. When you break it down boxing is supremely working class but there are lots of changes. Only one thing remains the same. Kids are being punched in the face for a living and there are repercussions at the end of their career. But we now live in a social media world and these days you hear boos more than cheers. A few years ago there were no boos unless you were a pantomime villain or a foreign fighter.”

The fighter shrugs and smiles. “It’s OK. People have a right to express themselves.”

Groves has survived a tumultuous two years with his intelligence and wit intact. Any bitterness, following the disappointment of three world title defeats, is curbed by his rejuvenated hope. Groves returns to the ring on Saturday against Andrea Di Luisa , a decent but unremarkable Italian, at the Copper Box in London. It is his first bout since a surprising split-decision loss to the unheralded Badou Jack in a WBC world super-middleweight fight in Las Vegas last September.

Paddy Fitzpatrick has been replaced in his corner by Shane McGuigan, the inspirational young trainer, and Groves seems galvanised. But, first, it is striking to hear him detail some raw truths after seven years in professional boxing. It becomes easy to forget we’re sitting in Carluccio’s on the Chiswick High Road, surrounded by affluent mothers and their babyccino-drinking offspring. Most of the women would probably be surprised to hear that Groves came close to beating a definitive hard man in Carl Froch in their thrilling first world title fight in November 2013 – only to be knocked cold in front of 80,000 at Wembley Stadium six months later.

Groves sounds philosophical as he details the affection and contempt he has experienced.

“You think back to 2011 when I boxed James DeGale and it felt like everyone in the country wanted me to win – even if they didn’t think I would. That was a brand new emotion. And when you win it’s amazing. Then you get to Froch. I was quite shocked how venomous people were when I said I’d win. It snowballed and people on Twitter were saying: ‘You’re going to come home in a body bag.’” He spears another dark mushroom. “You get numbed to it – but my mum and wife are upset because people say you’re going to die. I’d say: ‘Don’t worry – it’s probably just some kid.’ Then we box and I knock down Froch, we get the controversial stoppage in his favour, and everyone is back on my side and I’m no longer a c-u-n-t.”

Groves spells out that ritual insult and smiles. “I remember going to the weigh-in for the rematch and getting cheered while [Froch’s promoter] Eddie Hearn was seriously booed. The blood drained out of his face and I thought: ‘I’m really on my way up here.’ Then I got knocked out and I’m back at the bottom again. But no one stops me on the street to boo me. They always ask for a photo or say something nice. But I need to win something because now, even when they’re nice, it’s a sad conversation. ‘Oh man, it’s going to happen for you one day! Oh man, that first Froch fight … I thought you had it.’ I need to win something so they can say ‘Well done, mate …’”

George Groves (right) lands an impressive right-hand jab on Carl Froch during their WBA and IBF Super Middleweight title fight in Manchester. Photograph: Dave Thompson/PA WIRE

Groves expected to become a world champion in Vegas but he was knocked down in the first round by Jack. Showing typical tenacity, Groves got up and clawed back control of the fight. He was ahead going into the final four rounds but stamina and work rate drained out of him while Fitzpatrick sounded more like a cheerleader.

“He gave me the wrong instructions,” Groves says of his former trainer. “He was telling me: ‘Keep doing what you’re doing, you’re winning this clearly.’ But the rounds were much closer than he was seeing them. Even before the fight it was the loneliest I ever felt. I’ve always encouraged that feeling because boxing is a lonely business – but I felt isolated when I realized I had no confidence in Paddy. Before the fight I was in the bath and I could feel all this pressure – because I didn’t have any faith in him.”

Groves decided to start again with McGuigan. Having steered Carl Frampton to a world title and a huge unification fight against Scott Quigg next month, McGuigan is now training both Groves and another renowned boxer on the comeback path in David Haye. “Boxing’s very incestuous,” Groves says wryly, as he and Haye were stable-mates for years under Adam Booth. But the 26-year-old McGuigan, younger than all his three of his leading fighters, has transformed each of them.

“On paper I’ve experienced much more than Shane,” Groves says. “We were amateurs around the same time but I boxed at a higher level – I was boxing for England and then I turned pro and boxed for world titles. But Shane faced lots of pressure having the McGuigan name. I remember when I first met him as an amateur he was introduced to me as Barry McGuigan’s son. That’s a burden because Barry is a huge name. But Shane’s starting to have real success at world level as a trainer. “Shane is intelligent, he carries himself well and he has no ego. He’s quietly-spoken but he explains things very clearly and he’s not erratic. He’s studied his craft and he has an authority in the gym way beyond his years. But then we do pads and he has his cap on backwards. We look like two kids.”

McGuigan told me last week that Groves is “looking sensational in sparring.” His new fighter nods. “I feel really good with Shane. He’s taught me new tricks, changing the angle on some shots. Even though I’m 27, and a bit long in the tooth, I want to be open-minded and go with it. I’m really enjoying it and improving.”

Groves went to the O 2 Arena 10 days ago to watch Haye’s first round KO of the hapless Mark De Mori. “I didn’t know what to expect. It’s notoriously difficult to sell tickets there but it was almost full. It looked fantastic and there was lots of entertainment. Most people there were nostalgic David Haye fans who saw him 10 years ago for the first time. They came out to support him and didn’t care if he knocked out some fat geezer who never stood a chance. People who go see the Rolling Stones don’t complain that their hips don’t move like they used to. That’s not what it’s about. You go there, have a drink, a good night and see David bash up some fat geezer.”

He expects that, before facing Tyson Fury and Deontay Wilder, who both hold versions of the world heavyweight title, Haye will fight Anthony Joshua. Does he think Haye will beat Joshua? “Yeah – if he’s still got the reactions. We still don’t know what David’s got left but he’s always going to have punch power. Joshua is a great athlete but he’s still learning because the people meant to give him rounds couldn’t. Now he is a pay-per-view fighter so you have to make it work. I think David will fight Joshua after a few more bouts.”

Is he close to Haye? “I wouldn’t say there’s any animosity. We’re quite similar. When we meet it’s just chitchat –‘How you doing mate?’ We never have real conversations.”

Groves considers the changes in Fury. “I know Tyson quite well. When we were kids we boxed together for England. He was very different then. Now he’s totally mad. Super unpredictable. Back then he was confident but not that mouthy. He was a nice guy. He’s probably still a nice guy now … but he does and says crazy things.

“ I don’t think he’s that aggressive by nature. When he finishes boxing he’s going to be a chilled-out dude. Maybe he winds himself up to get aggressive. When I watched that clip with Wilder [Fury jumped into the ring after the American successfully defended his title in New York] it was like a momentum thing. He built himself into that rage to get another headline. It’s a bit crazy. But he doesn’t care.”

Does Groves still follow boxing closely? “I’ve never been the biggest boxing fan. If I know the guy I will watch him. But if it’s two great fighters and I don’t know either of them then I won’t bother. I like watching Frampton in the gym, and he’s in a proper fight against Quigg, so I guess I enjoy it much as I always did …”

Groves supports Chelsea and, he says, “my commercial agent deals with a lot of footballers. This footballer came over one day. He’s only 21, English, but he might never make a first-team appearance. After he left I said: ‘Is he a £1,000-a-week or a £20,000-a-week footballer.’ My agent said: ‘He’s a 38-grand-a-week player.’ This is a guy out on loan who doesn’t play a lot but he’s still earning £2m-a-year. Unlike a boxer, he doesn’t have to pay a trainer and you think: ‘Fuck me, I wish I could be a footballer.’”

He remains a fighter rather than a footballer and, despite the hardness and cynicism of boxing, Groves still yearns for a happy ending.

“I’m looking forward to a life outside of boxing but I don’t want to leave it quite yet. I’ve got a lot I still want to achieve. I am interested to see where I end up one day but at the same time I am petrified. I’m like a woman whose biological clock is ticking – I need to be married, have kids, win a world title and I am not leaving this arena until I’ve done it. I’ve earned some decent money, and bragging rights, and boxed on a Floyd Mayweather undercard in Vegas … but it’s a fraction of what I set out to do.”

Groves could finally win a world title this year but he has numerous testing British rivals – including the unbeaten Callum Smith and his old foe DeGale, the current IBF world champion. Are his wife and parents happy for him to continue fighting?

“Sophie has always supported me. But she’s also said as soon as your heart is not in it I won’t support you because boxing is too dangerous. So my wife has concerns and she asks: ‘How is it going with Shane?’ She’s feeling good now because I can answer honestly and say: ‘It’s great.’

“My dad goes into full dad mode quite a lot now. He gets quite philosophical and says: ‘You’ve got a lot to be proud of mate – you’ve achieved a lot.’ It’s almost as if I’ve retired. I’m like: ‘Dad, don’t worry … it’s not over yet. There’s still loads more to come.’”