For all the quirkiness and international success of his menswear - they revere him in Japan where his company has 320 outlets - Smith has never lost sight of the traditional shopkeeper's values that have kept him at the forefront of British fashion for decades.
It is perhaps not surprising that Sir Paul Smith should be standing in the gigantic new Apple store in London's Covent Garden, answering questions about his global business empire. He is good friends with Apple design guru Jonathan Ive and is one of the highly select individuals who regularly receive new products from the super-secretive Cupertino outfit before they hit the shops.
And while he is keen to point out to the attentive crowd that most of the designs for his 12 six-monthly collections are roughed out by his team in some way using a MacBook Pro, he still designs and makes notes using a pencil and pad: 'I never stop writing myself notes,' he says. 'I've got shoe boxes full of notebooks ...'
Alongside his traditional approach to design he offers a disarming line in modesty, stating: 'I'm quite good at business and quite good at design, but I'm not particularly fantastic at either.' Actually, he is rather good at both. Likewise, when he has commented that the Paul Smith concept is Savile Row meets Mr Bean - 'It's the love of everything Savile Row has stood for, or the Yorkshire textile industry, or the Northampton shoemakers, then with Norman Wisdom or Morecambe and Wise, with that sense of humour just sprinkled on' - it's worth remembering that the Mr Bean franchise has earned many hundreds of millions of dollars worldwide.
Most of the questions from the Apple audience are about the practicalities and logistics of making design happen rather than design itself: how to make design work in the big, bad world, how to turn a drawing into an object and then turn that object into money. This is what Smith likes talking about and, while he can speak about himself, and comment on design with great integrity and common sense, he knows, when it comes down to it, it's all in the selling. Because if you don't have a business then you don't have anything.
'When I started as a shopkeeper in Nottingham I was very aware of opening the door in the morning and closing it at night,' he told me. 'And being in a provincial town in the 1970s with local customers you had to make sure you had a shop that always changed. You had to make the windows exciting and keep things up to date. If you didn't, no one would take any notice of you. You had to be fresh, even though we didn't have much competition. People don't have to go into shops - they could just as easily go for a walk in the park. In a way, my first shop was quite confrontational.'
Smith's CV since is the stuff of British business legend. A fanatical young cyclist from Nottingham with ambitions to turn his hobby into a career, he was forced to change his plans after peddling into the back of a car, which led to many broken bones and a six-month hospital stay. He fell in love with an art student called Pauline, who opened his eyes to the visual world, encouraging him to become a menswear designer.
He opened his first shop, Paul Smith Vetement Pour Homme, in Byard Lane, Nottingham with all his £600 savings in 1970. The rent was 50p per week and the first week's takings were £52, as he became the first shop outside London to sell the likes of Kenzo and Katharine Hamnett. Open only on Fridays and Saturdays, he sprinkled the sales floor with Christian Dior's Eau Sauvage to mask the smell from his Afghan hound.
The business grew and in 1976 he bought a disused bakery in Floral Street, Covent Garden, but had to wait three years before he could afford to do it up and open it. The man is clearly patient.
Design blossomed as a cultural force in the 1980s and designers took on God-like status, as young urban professionals bought the trappings of the upwardly mobile: the Tizio lamp, the Breuer chair, the Dualit toaster, the Alessi kettle, the Tag Heuer watch, the Golf GTI convertible ... and the Paul Smith Prince of Wales check suit. Smith was a squirrel-like collector and sold quirky knives, notebooks and pens that he picked up on his travels. His most inspired find was the Filofax, a personal organiser he discovered at a tiny company hidden under an east London railway arch.
He sold suits to managing directors, but also to art directors and became famous for clothes which scream when you want them to, not when you least expect it. He had arrived. Smith then embarked upon a cautious, but comprehensive expansion plan, never overstretching himself or taking his eye off the ball.
So, in 2010 he now has 2,257 'doors' - 33 directly operated shops, 81 franchise shops, 491 department store outlets and 1,652 multi-brand boutiques. He designs three men's collections, a women's collection, an accessories line, jeans, shoes, you name it. But design and distribution are tightly controlled. And, while his womenswear is often said to be less influential than his menswear, it was a Paul Smith black and pink dress that Samantha Cameron decided to wear to the Conservative party conference this year.
Paul Smith Group Holdings, his Nottingham-based fashion empire, has weathered the downturn well. He turned in a £21.6m profit on £168.4m sales in 2008-09 and turnover this year will be north of £180m. In February 2006, his long-time Japanese licensee, Itochu, bought a 40% stake in the Paul Smith fashion brand and shops, sold to it by Pauline Smith and the designer's long-time business partner, John Morley - leaving Smith still with a near 60% stake. He paid himself around £4m last year and The Sunday Times Rich List says the business is worth £250m.
You can read a hundred different articles about Smith that will re-emphasise his studied eccentricity, his devotion to 'classic with a twist' clothing, his obsession with peppering his stores with old toys, vintage books and cute Japanese gadgets (I've written many of them myself). You'll read about the elegantly cluttered office too: piles of old magazines (Town, Nova, Vogue, i-D), a bicycle, a model scooter, almost as many books as your local branch of Waterstones, several paintings, a singing fish, a collection of iPods, a statue of Godzilla and dozens of small cameras.
Smith's inner sanctum is an Aladdin's cave of designer kitsch and cutting-edge design, a hodgepodge of pop cultural titbits, a cornucopia of the arcane, the absurd and the supremely elegant. 'The office is the equivalent of my brain,' he'll say, smiling.
But what you rarely read about are Smith's business skills, his retail acumen or his merchant's common sense. Sadly, many in the world of fashion lack these attributes. You cannot survive on tantrums and tiaras alone. Smith is part designer, part retailer and part showman, which makes him unique. He's completed VAT returns, posted invoices and packed boxes. He still does a job he clearly hugely enjoys.
The Paul Smith brand is known the world over, from London to Tokyo, from New York to Shanghai and most points in between, yet the designer hasn't expanded for the sake of it. The company has never borrowed significant sums, always tried to own its premises and not diversified into areas in which it has no relationships or expertise. 'In the past 10 years, you've seen a lot of publicly owned companies being pushed to open more and more doors to meet the return on their investment. We haven't had to do that,' he says. 'When we do open a shop, we care about it and make sure it has its own character. Our brand is not about having a shop on every street in the world. I think the rapid expansion of many luxury brands is what contributed to the financial situation we are in now. There is too much out there, too much stuff. Too many people trying to fish from the same pool. You used to be able to go to Capri and find something different, but it is now all the same brands there that are everywhere.'
He's not as big as Prada with its EUR2bn (£1.7bn) turnover and prospects of a Hong Kong listing. And he hasn't become the UK's Tommy Hilfiger - for which we should, maybe, be grateful. He knows that had he been driven more by money and less by his very particular English vision, he would 'definitely not have been so successful and definitely not been so happy'.
Paul Smith. The name says it all, really. Simple, straightforward, easy to get your mouth around. He admits that a lot of his success, particularly in the early days, was due to his charm; he manages by nudging people rather than pushing, cajoling them towards his point of view. He is one of the few people I have met who, fleetingly, can make you feel like the most important person in his world. The Beatles producer George Martin also has this ability and, even though you know he does it to everyone, you don't care. Smith has always said that he gets his personality from his father, Harold, a credit draper (travelling salesman) and keen amateur photographer who sold curtains, clothes and shoes and had a particular talent for making people feel relaxed. Sir Paul's background was comfortable: 'Excellent mum, quirky dad - an always stable relationship.'
If pushed, the chief architect of British menswear will admit to finding himself a bit of a bore. 'Sometimes I think I'm too bloody nice for my own good,' he told me, 'because I come across as being so slimy sometimes, it annoys the hell out of me, so God knows what it does to other people.'
In many ways, Smith has tried to demystify the fashion world, not least for himself. While a lot of fashion designers during the 1980s and 1990s were wilfully insolent, fostering a keep-off-the-grass mentality, Smith was always at pains to present a non-threatening environment, in his advertising, in person and - perhaps most importantly - in his shops. 'I hate shops that are museums, or boxes,' he once told me. 'I like the smell of polish. I like the feeling that someone cares.
'I suppose my thing has always been about maximising Britishness. Paul Smith clothes have never had anything to do with class, in fact they've always tried to subvert any of those connotations. I've made a point of mixing styles to such an extent that they becomes classless - and street fashion has obviously helped in that regard. Posh with kitsch, matt black with tat ...
The classes have always appropriated each other's clothing, whether knowingly or not, and I suppose I've exploited that to a certain extent.'
He loves British non-conformity: 'We've got the most extraordinarily creative people here and the ingenuity of each new generation never ceases to amaze me. Other countries might have a larger quantity of better dressed people, yet they all look the same to me.
'We have a much more lateral way of thinking about everything, from the way we dress, to the music we make, to the things we consume. The British are free spirited ...' An Italian designer of my acquaintance once decreed that none of his female employees was to wear dark-coloured tights, nail varnish or high heels, either in his offices or on the shop floor. The idea would be anathema to Smith.
The company nerve centre remains in Nottingham. It is a huge operation, yet still manages to feel family run. When I asked Smith why he thinks he inspires so much loyalty from his staff, he said: 'Maybe because I'm a laugh. Because I'm silly.'
But beware the man holding the rubber chicken and introducing you to his singing fish (there was a time in the late 1980s when Smith liked nothing better than showing visitors to his Covent Garden office his singing fish: 'Take me to the river, drop me in the water ...'). Smith is shrewd. And he is determined to do things his way, even if he sometimes likes to imply otherwise.
'This year we could have redesigned a couple of hotels, done a car, half a dozen mobile phones, but why would we? We make clothes, we don't do phones. Some designers will put their names on anything.'
In the early 1990s, some of Smith's staff tried to convince him that the time was right to sell the company, and, even though he was dead set against it, he allowed them to start the process, more out of curiosity than anything else. 'In the end, the staff turned to me and told me I was right, we were doing fine as we are and didn't need to sell out to investors or a bigger group. We're a big company, but we're big on our own terms.'
He is certainly big in Japan. Smith was one of the first British designers to try and break into the Japanese market. He did it through dogged determination, travelling there dozens of times a year, learning the Japanese way of doing business and taking his partners tremendously seriously. Sir Paul has been to Japan nearly 100 times and has about 320 outlets there. He says many European designers have failed in Japan 'because they didn't roll their sleeves up and try to understand the market'.
I accompanied Smith when he visited Tokyo on one of his trips in 1995 and it was like travelling with a rock star. I remember one scene when he had just stepped out of the lift on the ground floor of the Tokyo Fashion Institute, only to be mobbed by a hundred-odd Japanese fashion students dementedly brandishing their autograph books and firing their flashguns like automatic pistols. As Smith smiled for the cameras and signed everything that was put in front of him (books, magazines, socks, T-shirts, bits of old tissue paper), the crowd closed in, touching his jacket, bowing, grinning and laughing. 'You're very friendly,' said Smith in a typically understated response. 'Very kind and er ... very friendly.'
He still travels to Japan regularly and shows no signs of slowing down or wanting to hand over any of his responsibilities to anyone else. After all, as many other name-brand designers have discovered - such as Ralph Lauren and Giorgio Armani - what do you do if you are the brand? What do you do if the brand is you?
And where does he stand on succession, the issue that every brand custodian has to contend with? After all, can there be a Paul Smith brand when there is no longer a Paul Smith? 'I will keep going while I have my health and the energy to stay involved,' says the 64-year-old who received his knighthood in 2000 and then married his long-term girlfriend, Pauline, on the same day. 'When I eventually go, the company would become much more of a brand, but it would still possess the same brand principles. I can see us setting up some sort of foundation, but I don't like the idea of just passing the brand on to someone else while I don't have to.'
Smith, who subscribes to the 'I win, you win' way of doing business and goes out of his way to be funny, charming and gregarious, has spent 30 years building the persona of a wacky, eccentric Englishman. It is a strong persona, a strong brand, and it has made him famous all over the world. But he does admit he has weaknesses.
'I am not very good at confronting problems, whether it's a business matter or a person. I tend to nod and move on and try and deal with it later. I am Cancer, a crab, and I cling on to things for too long. My other weakness is that I like being liked, and I think that I can be really soft because I don't want to argue with people. So I am not particularly bolshie with people. I don't like to shout. I would sooner discuss and work it out. Lots of people who have left my company come back as they like the atmosphere and the culture here better.'
Smith's innate shopkeeper mentality is reflected in his increasing distaste for the casino culture of the banking world and his refusal to expand his brand beyond its means. He also thinks the coalition is right to impose public spending cuts, although he doesn't think the banks have paid a big enough penalty for being so cavalier with their investments.
'Unfortunately, I think the Government is right to do what it's doing. It has no choice, but it's an awful job nonetheless. It's really unfortunate that the people who have run the country into the ground are not the people who are paying for it. The bankers have got off scot-free, and the people who are actually having to lose their jobs or have a wage reduction were not guilty in the first place. It is an outrage really.
'I don't think you can say it was the Labour government which got us into this mess; we were living in a time when we were all encouraged to borrow more and more, which is something I've always been deeply against. It's just greed and people wanting more than someone else. I have always guarded against this and would smile when someone opened 60 shops in a year, because I know what you have to do in order to do that.'
Even if Smith does step down from running the company, I can imagine he'll still want to pop in and muck about in his office - which might make things awkward for whoever takes over. After all, someone will have to tend to that singing fish.
My suspicion is that Smith will only contemplate departure when his wife says so. Like many sensible men, Smith listens to his wife and has done so for decades. Pauline was instrumental in helping him start his business and hugely influential in its development.
'Pauline is down-to-earth and very clear in the way she thinks. And we both want the same things. A lot of people who become successful want to have a bigger house or a bigger car and it is usually because of peer pressure or showing off. Pauline has always shied away from that sort of stuff. We are not overly extravagant.
'She originally gave me the confidence to go for it, to branch out on my own. She realised that I had all this energy and enthusiasm. She fostered that, channelled it.
'Pauline also has very clear opinions about the Paul Smith brand, especially regarding what we should and shouldn't get involved with. And yes, she might have a view about when I need to stop running around.'
Smith still loves what he does. I remember another vignette from Japan. Wandering through the labyrinth of overstocked shelves and heavily laden rails in his Shibuya office you could see the designer in his element. Smiling, almost giddy with excitement, he bombarded his assistants with questions, making ridiculous unprompted jokes and barking out orders like a football manager. The designer picked up a shirt, examined the cut and colour before saying, to no one in particular: 'I love this shirt. I love what I do. The possibilities are endless, you know ... absolutely bloody endless.'
THREE CHALLENGES FOR SMITH
To ensure that whatever plans he has for succession in his empire are seen through smoothly and successfully
To make his womenswear line as successful as the men's
To steer the brand through more difficult economic times without compromising its strengths and values
SMITH IN A MINUTE
1946: Born 5 July in Beeston, Nottinghamshire. Left school at 15 to become errand boy at a clothing warehouse
1970: Opens his first shop, Paul Smith Vetement Pour Homme, at 10 Byard Lane, Nottingham
1979: Opens his first London shop in Floral Street, Covent Garden
1984: Signs licensing agreement with Itochu of Japan. By 2002 Smith has 200 shops and 500 wholesale customers there
1997: Cool Britannia. Smith joins Blair government Creative Industries Taskforce
2000: Knighted in Queen's Birthday Honours List
2010: Opens first standalone women's store in Mayfair, London.