But here he is in the unlikely setting of Hay-on-Wye, Wales, and even more improbably, feeling intimidated by a group of ladies-who-lunch. "Bloody hell, what a racket," says the man who used to be able to start an argument in an empty recording studio. He wonders what his former charges might be doing. "Being Mods in London, most likely, while I'm dressed in a Barbour and wellies in the middle of nowhere. I really don't think they'd recognise me now."
McGee has a text relationship with Noel Gallagher but hasn't seen him or kid brother Liam for a while, though he's heard the latter's new band, Beady Eye, and pronounces them "pretty rockin'". What was the last CD he bought? "Good question." And his last gig? "Cannae remember." It's apt we're talking in Hay-on-Wye, scene of the literary festival, because books are his obsession now, although being Alan McGee, they're strange books. "I'm big into Aleister Crowley," he confirms.
But McGee, now 50, is very much up for recounting the story of Oasis, Creation Records and how a "daft laddie from Mount Florida Primary in Glasgow" got to be so rich and famous. The reason is the film Upside Down, a rockumentary about his old label. "I thought it would be rubbish. The two Creation books were. One was the accountant's tale and the other was a rush-job based on only two interviews. But this loony Irish director [Danny O'Connor] has made a brilliant movie and I think he's going to be a star."
Upside Down seems to have encouraged McGee to reclaim his mythology. He reveals there are no fewer than three other films recalling Britpop currently in development, to which he's either given his blessing or signed up as a main participant. "One will be about the drugs we all took and another one is called Svengali." Where does he think he stands in the hit parade of rock's charismatic megalomaniacs? "Well, in Britain there's probably a top four. Andrew Loog Oldham [Rolling Stones] is No 1. Malcolm McLaren [Sex Pistols] and Tony Wilson [the Factory supremo] are both dead so I'm claiming the No 2 spot. No disrespect to Geoff Travis [of the Rough Trade empire] but I'd rather get piles than watch a film about him." He enjoys his own joke some more. "Yes, a film about Geoff would be about as interesting as a haemorrhoid."
But if you're thinking Upside Down is a hagiography, you'd be wrong. The film expects McGee to brag but it also gets him to be self-critical. "I was a wanker," he says at one point. Later: "I was a professional drug addict." And again: "I actually thought I was up there with Beethoven and Shakespeare – I was absolutely delusional."
The movie is being premiered at next month's Glasgow Film Festival and our story begins in the city the night Bobby Gillespie, too young to attend a Thin Lizzy gig by himself, knocked on the door of his slightly older school-pal McGee. Gillespie would go on to become the singer in Primal Scream – one of the great Creation bands alongside Oasis, My Bloody Valentine, Jesus and Mary Chain and Teenage Fanclub – and author Irvine Welsh says in the film that the relationship between these "two old-skool Glasgow punk-rockers" was crucial.
But didn't McGee want to be a rock star? The man in the country casuals says not. "My band, Laughing Apple, was just a hobby band. In 1981 we packed it in after a horrible night in Edinburgh, playing to a bunch of squares at the university, which ended in a fight, our bass guitar being stolen and the van being written off on black ice." The McGee of this period had a cartoon-shock of ginger hair.
The film spreads the Creation credit around, and McGee's trusty accomplices were Joe Foster and Dick Green, the latter recalling a first impression of McGee as a "mad, totally overpowering presence". McGee was drinking away the £700-a-week that London club-nights were earning him until good, old-fashioned "Protestant guilt" took hold, the label being formed in 1983. Have any of the other traditional Scottish personality traits proved useful? "Well, I think from my mum, who died 20 years ago, I got my astuteness in making money and my dad was a cunt, basically. I don't mean that he was horrible, just stubborn in that very Scottish way, which has been invaluable. He's still alive and finally, at 77, I think he's softening."
McGee, a former British Rail clerk, got into music to avoid proper work. "Luckily I met a genius called Noel Gallagher and 60 million records later I'm still dodging any real graft." Oasis were discovered by McGee, propping up the bill at King Tut's Wah-Wah Hut in Glasgow [where he had to meet a model but found Oasis, better than a model].
Noel remembers his star-maker like this: "White jeans, red shoes, red hair and looking like he'd been on acid for six months – I just thought, 'What the fuck?'"[ahahaha] McGee, who was with his little sister, Susan, was convinced after the second song. "I fluked getting them because I was there."
With contributions from almost all the prime movers and groovers, Upside Down offers insight into McGee's business practices. He stage-managed riots to get publicity for the Jesus and Mary Chain gigs. Armed with an unwieldy first-generation mobile phone nicknamed "the cosh", he stole Ride from under the noses of Warners. When My Bloody Valentine went over budget, he feigned a nervous breakdown to get them to finish their album. And to investigate the nascent sounds of acid house, he moved to Manchester and "went mental for a year". He told his bands about this thrilling mix of indie and dance. "Bobby [Gillespie] got it and so did Kevin [Shields, My Bloody Valentine] but when I took Guy Chadwick [The House of Love] to a club all he did was take his clothes off."
All this hedonism took its toll on Creation, however, and especially McGee. One female member of staff admits in the film: "The first time I ever took Ecstasy was at work." Drugs were couriered to the office and another employee recalls McGee's loudspeaker announcements ordering them into the "bunker" following the latest delivery. But, en route to America to cement his reputation as the industry's pre-eminent party animal, he collapsed on a plane and had to be carted off by paramedics. Noel Gallagher says Oasis' greatest successes were "tinged with sadness" because McGee missed them as he cleaned up and dried out.
McGee says now: "I don't regret anything. When I turned 50 I was able to accept that everything that happened to me was written before I was born. Heroin wasn't my drug of choice, although I wasn't adverse to the odd dabble to bring me down. I did Ecstasy, cocaine, acid and everything else and I had a blast." Creation lost its independence to Sony and shut down for good in 1999.
"Maybe Oasis playing to half a million people at Knebworth  would have been the proper time to stop, but that would have meant missing out on Britpop. Everyone in the UK seems to hate Britpop now, but in places like Italy where I'm DJ-ing this weekend, they still want to talk about it.
I don't regret those canapés with Tony Blair. I quite like him as a human being, although I haven't seen him in years either."
McGee, who also has a son from his first marriage, lives quietly with his second wife, Kate Holmes, and their ten-year-old daughter, Charlotte, on a leyline "in the middle of bloody nowhere". During his DJ turns, "waving my hands in the air for a thousand euros a night", he accepts a friend's description of him as a "camp, Scottish Mick Jagger".
He buys and sells property and has been known to make profits of 1000 per cent. He scours secondhand books shops for rare copies of Crowley's books plus other occult and chaos magick favourites. But mostly he likes being a "housedad".
"I'm a really difficult person," he admits, "and I don't think I'd like to be related to me. But Kate and Charlie love me for who I am and everyone else just has to put up with Alan McGee. Do I think I'm lucky to still be here? Of course. Coming from Scotland I did used to think I'd be cauld by the time I was 60, although these days I'm trying to be a bit more optimistic. And do you know that only this morning Charlie told me she expects me to still be around when I'm 110?" Well he did once know the know the Live Forever guys …