David Haye says he dreamed of this day as a toddler - he's on a whistlestop media tour as heavyweight champion of the world.
In 36 hours like few others, the fast-talking south Londoner has gone from being a merely well-known British boxer to a genuine global celebrity.
And he is not hanging around after his giant-killing defeat of towering Russian Nikolay Valuev to win the WBA title on Saturday.
The bout, where Haye - a fine muscle-bound specimen but 'only' 6ft 3in and under 16 stone - took on a man seven stone heavier and nine inches taller, and won, captured the world's imagination.
DAVID HAYE FACTFILE
School: Snowsfield, Southwark
Family: Wife Natasha and 18-month-old son Cassius
Lives: Splits time between London and northern Cyprus training base
Turned pro: 2002
Fights 24 Wins 23 KOs 21 Losses: 1
It literally was David v Goliath, and although some boxing experts predicted a Haye victory, much of the wider public thought it just could not happen.
"I dreamed about all this when I was a toddler, it was just a case of what weight I would be," says the 29-year-old from Bermondsey.
"I started boxing when I was 10, and told everyone at school that when I was older, I would be world champion."
As Haye saunters through the corridors of BBC Television Centre in west London, with a bemused following of various producers and programme runners, he spies tennis star Serena Williams on a TV screen being interviewed in the same studio he just left.
"Would you like to meet her?" I ask, caught up in the moment, offering something I might not be able to deliver.
"Not today," he says with a contented smile.
Haye is moving awkwardly, limping almost. Not quite the Muhammad Ali-style 'float like a butterfly, sting like a bee' character who out-thought and out-fought Valuev.
He went into Saturday's showdown nursing some minor niggles, but gently refuses to go into details.
"Just the sort of injuries an athlete picks up," he says.
The day began on the ITV sofa with Lorraine Kelly and quickly, albeit somewhat chaotically, proceeds to the BBC breakfast show equivalent, then a 5 live studio, and BBC Worldwide.
Millwall fan Haye finds out our man supports rivals West Ham
"Where does that go out then?" he jokes. The banter is lost on some in a crowded Green Room as he waits for another interview.
The other guests bear looks that suggest they cannot quite believe he is in their company.
A canny young woman seizes the chance in between questions, texts, calls and general mayhem, to ask if Haye would be interested in doing some charity work.
Haye takes the plea in his stride like a gentle jab from a toiling opponent.
"It's for the Princes' Trust - we help young people get back into..."
Before she can finish, there's a "for sure" from Haye and there is another contact to note down.
Noting the numbers, taking the succession of calls, dealing with endless requests and generally being helpful is Haye's right-hand man Danny Watts.
It turns out he is a former amateur boxing champion whose scalps include 2000 Olympic boxing gold medallist Audley Harrison.
Watts joined the Haye camp late in the day, and seems to play the same kind of supporting role that Terry McCann played to Arthur Daley in the 1980s TV series Minder, only he's more upbeat.
Haye sits down for post-fight BBC interview
Big Dan, as he's known, is five inches taller than Haye at 6ft 8in so proved a good sparring partner ahead of the Valuev bout, and knows his way around the boxing circuit.
"I was in the opponent's dressing room after Saturday's fight as you have an observer from both camps to make sure everything is in order," said Watts, 36.
"They were taking the bandages off his hands. I'm sat down next to him, and he's got this big head and he's grunting, and then in walks promoter Don King. It was surreal.
"Twelve weeks ago, I was a scaffolder from Peckham."
Haye took the first steps on the journey to being a world champion at the Fitzroy Lodge Amateur Boxing Club in Lambeth.
Six years later in 1996, he went with his mum to watch Valuev fight at Battersea Town Hall. The Russian inflicted a quick defeat on Neil Kirkwood.
"I don't remember a lot about it, except Valuev's size," says Haye.
Thirteen years on, his mother is still involved, berating him with a text message amid Saturday's big-fight hullabaloo, for calling his opponent "smelly".
Haye is a friendly, down-to-earth, family man with a mischievous sense of humour, according to friend Cathy Brown.
Former female boxing champion Brown, 39, worked with him most days for several years.
Brown trained with Haye every day for several years
She trained alongside Haye at the Thirdspace gym in London's Soho as they were both managed by Adam Booth, who also sent them on gruelling sessions near his Kent home.
"We used to train together five or six days a week, so I got to know him pretty well," said Brown, who is 5ft 1in tall and weighed eight stone at the time.
"It was quite funny sometimes what Adam put us through, and quite draining.
"He used to get us to push a car up this long road, which was on a slope. David would go first and was a lot better than me, but then he was a bit of a big lump."
Flyweight Brown fought for five world titles, including the women's WBC and IBF belts, and lost them all on points decisions from judges in Germany and Italy. Haye was there at ringside.
"That's why I was really worried about the decision on Saturday night - it was quite a close fight, and I thought they might have gone with Valuev bearing in mind what happened with my decisions," said the former European champion.
For the record, one judge rated the fight as a 114-114 draw, while the other two gave it as 116-112 to Haye, the latter two exactly matching the scorecards of BBC Radio 5 live's commentary team.
Haye, whose 18-month-old son Cassius is named after heavyweight legend Ali's original name Cassius Clay, wants to emulate his hero by unifying the myriad of heavyweight titles.
"David always admired boxers Roy Jones Junior and Sugar Ray Leonard," adds Brown.
"Think of a boxer's name and you might think of Muhammad Ali or Mike Tyson. He wants to be up there with the big names."
Relive the moment when David Haye clinched the title
Haye's next fight will be a mandatory defence of his WBA title against John Ruiz, which will probably take place in England in the spring of 2010.
Then there is the enticing prospect of a summer showdown with one of the champion Klitschko brothers at a big venue
"He would destroy Ruiz and there's unfinished business with the Klitschkos," said Brown.
So will the fame and money change the boy from Bermondsey? Possibly not.
"He's serious about this boxing, but he's a really jovial, mischievous bloke who loves doing wind-ups," says Brown.
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