The name's Corden, James Corden
After winning millions of fans in all those 'fat' roles, James Corden saw his career implode on a wave of booze, broken hearts and mediocrity. But now he's finally got his act together.
"The person I look back on, two-and-a-half years ago, I don't really recognise as me," says 33-year-old James Corden in a thoughtful, reflective voice, sounding absolutely nothing like his cocky alter ego Smithy from Gavin And Stacey.
Remembering times of partying, drinking, ignoring phone calls from his family and being rude to his agent, he's still embarrassed about letting the hype go to his head.
"I wasn't in AA or anything. I just got a bit lost. I was heartbroken and a little bit famous... and that's a bad mix," he says, momentarily allowing his childish grin to break through the introspection prompted by his new autobiography May I Have Your Attention, Please?
The past decade has been a "rollercoaster", Corden admits. After landing a part in West End musical Martin Guerre aged 17, he went on to star in ITV's Fat Friends (where he met future Gavin And Stacey writing partner Ruth Jones), was cast in the National Theatre's international tour of Alan Bennett's The History Boys, which ended in a film adaptation, and then created and starred in seminal comedy Gavin And Stacey, a series that garnered a level of public devotion not seen since the likes of The Royle Family.
"That for me was more interesting than Star Wars," he says of Caroline Aherne's ground-breaking domestic drama. "It was like a mirror: there's my dad and mum, elder sister and her boyfriend, now husband, and dad's got the remote..." he tails off, giggling.
"I had a burning thing inside me, that I always wanted to play proper parts in things. I thought, I'd rather write, than constantly be the person stood at the back."
For its 2010 finale, the Gavin And Stacey show he co-wrote with Jones pulled in 10 million viewers. Backstage though, as television's chubby golden boy explains in new book, he wasn't happy. And Corden fans probably won't need an autobiography to tell them why.
Riding high on a crest of professional success, when mediocrity hit it was a bitter blow. His sketch show Horne & Corden, debut film Lesbian Vampire Killers - and even James Corden's World Cup Live, an apparently harmless ITV presenting gig - were labelled as drivel by critics. And Corden is nothing if not honest about why he failed to deliver the goods.
"Trying to write a TV show, or be in things and be good, and going out all the time, are mutually exclusive. You just can't do them both.
"You feel like you can, because you're still handing in the work - it's just not very good. Not to say it's awful, but it's not good enough."
As well as the heady rewards of fame, Corden was also struggling with being single for the first time, after his nine-year relationship with Shelley finished in 2007, and his Gavin And Stacey co-star Sheridan Smith ended their "turbulent" affair two years later as he finished filming Gulliver's Travels.
So Corden rented a fancy north London flat with Mamma Mia's Dominic Cooper, and his socialising took on an epic quality.
"At one point, for about two weeks, all Dom and I had in the fridge was some vodka, a bottle of pink vitamin water and a Lindt chocolate bunny," he writes.
Parties once or twice a week followed, with Cooper "smashing the c**p out of a ludicrously massive electric drum kit he had bought". The noise became so bad that Camden Council threatened to fine them £25,000.
"Lots of people go to university, get really drunk, and wake up in bed with people they shouldn't... but I went straight into a West End show, was in a really stable relationship and had a flat, and then slowly those things disappeared," Corden points out, philosophically.
Soon his conscience, and his family, came to make their feelings known. "I was aware I'd been on a rollercoaster. But I didn't realise lots of people who cared about me had been on it too.
"It's only speaking to my mum now and she'll go, 'Oh my God, we were worried about you'. I'd drifted so far away from the boy they had raised."
After his parents made an awkward, impromptu visit, terrified by reports in the papers of him falling out of clubs and bars, their worried looks were enough of a rebuke.
"There were no 12 steps, it was as simple as saying I'm going to stay in, and I'm not going to kiss anyone unless it could be 'someone'.
"Of course I didn't always stay true to that - but it worked on the whole," he smiles.
That's a huge understatement. Corden's now in a steady relationship with charity worker Julia, has the lead in One Man Two Guvnors, transferring to the West End this autumn, and is the proud father of six-month-old Max.
"It was my birthday yesterday, and me and Jules ate sushi and watched Breaking Bad. And we didn't even finished the second episode. The baby started murmuring, we were asleep by 9.50pm."
While he and Cooper are still best friends (he lives a few doors down) their mutual party days are behind them, for now.
"I saw Dom the other day, he was sitting on our front step on his laptop, hijacking our wireless to send emails because his doesn't work in his flat.
"'Wow you really haven't changed' I thought. 'You're on all these big movie posters, but you're so uncool right now, you're stealing wi-fi'."
Another friend he'll never lose is Ruth Jones. "The truth is, if you get to sit in a room with her for a few hours a day, it's the luckiest place in the world to be.
"She's the most amazing company, coupled with an incredible creative mind. And when I was sort of, you know ..." he stops and laughs ruefully about his partying days. "Well, one time I turned up at Ruth's at six o'clock, fell asleep on the sofa and didn't wake up until nine o'clock the next day. She'd put a blanket on me.
"It's the absolute truth that for a couple of years she was absolutely my only constant. My anchor."
Corden is still learning to reconcile the highs and lows of his career, especially since he worked so hard to create professional opportunities for himself early on.
"At school there were three boys in the same play and the other two got the leads. The only thing that separated me from them was that I was heavier. And it pushed me."
Today, he looks slimmer, and admits to having a personal trainer (he used to share the same one as David Cameron). But an even leaner silhouette seems unlikely at this stage.
"I would like to be.... [long pause] ...lighter, and it's a struggle, a constant battle... because I love sandwiches so much."
Moving from deep reflection to gales of laughter in one sentence, the shades of light and dark in his character spread out like a rainbow.
"Sandwiches are amazing - they make me believe in God," he continues. "They can only have been sent by a supernatural being bigger than all of us. And cake. And as much as I love a fruit salad, it's never the same.
"I mean I don't sit at home guzzling. I've had half a grapefruit and some sushi today... but there is not a doubt in my mind that my life would rapidly change if I could stop eating toasted sandwiches.
"And the trouble with those training sessions is that they make me think. 'Well I've done training today, I can have a sandwich."
May I Have Your Attention, Please? by James Corden is published by Century.