Can this really be Giorgio Armani? Midway through our conversation, held on a leather corner sofa by a bar a-brim with vodka, I'm wondering. To begin with, he was an hour late; yet during the 40 years in which he's built his fashion house - of which he remains the sole shareholder - Forbes magazine estimates his personal net worth at £5.5 billion ($11 billion) - Armani had made it his mantra to always be the first man in his Milan office. His biography says he even becomes edgy (and he has a temper) when his staff dally at the coffee machine for their morning espresso.
So Armani doesn't do late. Except, strangely, for today. He's been closeted backstage in this gleaming limestone Mussolini-built, Palladian-proportioned marble Palazzo delle Civilta that Roman locals call the "square colosseum", making lengthy last-minute adjustments to the evening's career-spanning One Night Only fashion show.
This has well over 100 looks, a front-row that includes Tina Turner and Milla Jovovich, and is followed by a party for 600 that continues full-tilt until 4am.
The carved white letters that spell Armani's name on the steps outside are each only marginally smaller than a Stonehenge obelisk, and the spotlit clothes in his Eccentrico exhibition downstairs, a physical catalogue of some of Armani's most whimsically extravagant designs, fill two cavernous halls.
As well as lateness, Armani-lore dictates that he neither tolerates the ill-prepared nor the inappropriately attired - even as a teenager he was telling his schoolmates what to wear.
So my navy Armani jacket is on and my head crammed with esoteric Armani facts.
Sadly, however, I don't speak his language. I open in my A-level French (he is fluent) but gentle shivers afflict the Armani features - as if confronted by a coat cut clumsily by some dubious designer - and he suggests I stick to English (which he understands, but does not feel confident being quoted in), while he answers in Italian (which I sort of understand, and which is being translated).
We start with some pleasantries about Rome - "here there is nightlife, and the food ... but in Milan there is nobody on the street after 9pm. It is very snob" - before roaming fashion-wards.
After all the shows he has held - from his shoestring start-up days in the 1970s to the high-production spectacles held in his purpose-built Milan theatre today - has Armani developed any rituals? He glances at the bar, and says: "Well before the show I'd always like to have a vodka. But no, the only thing I do is to always wear the same watch" - there is a slim, gold-encased timepiece on his wrist - "it was a present". (He won't say from whom).
Deploying that biography-based revision, I quote something he said to Eric Clapton in the 1990s: "The more successful I become the more I want to remain like me, with my defects and insecurities."
Insecurities, Mr Armani? He laughs: "Without insecurities I think one becomes a little bit of an idiot. Yesterday I had all of the girls in this show with a particular hairstyle. Today I don't like it, so," - he shrugs - "I've changed everything."
Armani started late - he was 40 when he founded his business in 1975 but it grew rapidly.
"In the beginning it was down to courageous and slightly mad intuition, rewarded by good luck," he claims.
In 1978 Diane Keaton wore one of his deconstructed jackets to accept an Oscar. Two years later, he outfitted the cast of American Gigolo - which was originally set to star John Travolta. "I met him when he came for the fitting; he is very funny and charming. But without taking anything away from him - because he is such a great actor - he wasn't the one for that role. Richard Gere was spectacular, and Lauren Hutton ... so beautiful."
These unplanned coups, and later the impeccably connected management of Armani's Los Angeles representative, Wanda McDaniel, made him the first international fashion designer to win star billing in Hollywood.
Asked about the red carpet now, he says: "It's a business. Although nowadays wearing something by Armani on the red carpet is more prestigious, I think - because with so many other brands you know that it has been paid for. So if you see someone wearing Armani, you know it is the choice of the celebrity. It is honourable."
We discuss his dislike of sound-and-fury trends, or "fake revolutions", which he dismisses ruefully as "marketing". And on old fashion houses - I mention Yves Saint Laurent and Givenchy - that continue under young designers whose aesthetic has but the barest connection with their retired or dead founders, he says: "It's more marketing.
Marketing is not a nice word, but the world is about marketing now."
Certainly, when it comes to the M-word, Armani is no slouch himself and his campaigns' stars have included everyone from Cate Blanchett to the Beckhams, and his One Night Only event is a carefully constructed coup de theatre.
As well as that punctuality, Armani has a reputation for being fearsomely controlled, obsessive about detail, and not necessarily a laugh-a-minute guy. So it's when he starts chuckling as I ask about the wardrobe in his Milan home - it is apparently so enormous it has 48 doors - that those doppelganger doubts set in.
"Yes, there are doors everywhere, all of them covered in mirrors. I'm not sure I like that too much though, because waking up and seeing your face reflected 48 times can be very difficult."
And then there is just the slightest aside in his biography, suggesting he once took LSD.
"Si, si," Armani concurs cheerfully: "I'd better tell you the story. It was a long time ago, we were in the office, and we had finished work exhausted. A friend of a friend said, 'Hey, take this it will give you energy', so I thought I'd try it. I didn't know what it was. It made me laugh and laugh, like crazy ... to the point that my back hurt," he holds his hips, "like I'd just had a baby."
After Armani made the cover of Time magazine in 1982 - he laughs again as I ask him about Valentino approaching him on the street shortly afterwards, leaning into his ear and saying just "My, my", before walking on - he told an interviewer his first thought was "I must do better".
Thirty-one years later, aged 79, does that still apply? "I must always try to do better," he says, "because perfectionism, and the need to always have new goals and achieve them, is a state of mind that brings profound meaning to life."
Ah, now that sounds like Giorgio Armani.