Today, it's safe to say that, despite the fact that Master Conran has reached that certain age, he looks like the proverbial spring chicken, nut-brown, impressively wiry, and younger, if anything, than the last time we met. He's very pleased to hear it.
"Do you think so?" he says, squirming in his seat at a busy restaurant in the heart of Chelsea (not, in case it matters, one of his father's), more than happy to play the coquette as he places what must surely be the largest olive known to man into his mouth.
So, how does it feel to be 40, I wonder?
"Since I'm only 39-and-a-half currently, I really wouldn't know," he deadpans. "You know, I don't like anniversaries. They're so ageing, don't you find?" Conran's birthday is, in fact, not until December. However, for practical reasons, he says, he chose to celebrate his auspicious age in the height of summer.
"Well, you won't be able to buy a bottle of Champagne this December, will you? It will be all sold out - or at least double the price. To tell you the absolute truth, I don't think there's anything good about being 40 at all. It's just that you're older. Oh, I suppose that you're wiser and have more experience. But that's it. You have to start fighting everything, everything starts dropping, or so I'm told, it all just falls to the floor!"
Not that a little thing like that would stop Conran in his tracks. "I'm a very hectic person. What can I do about it? I'm not going to change. The idea that one becomes more mellow, that's just..." He searches for the word then delivers it with a flourish: "Bollocks."
If this all sounds rather frivolous, flip even (and there is, indeed, a determinedly playful side to Conran), it belies the fact that, over the past 10 years, the designer has rescued his company from the brink of bankruptcy and now oversees an impressive 22 lines - from Jasper Conran jeans, to childrenswear and even a new line for Waterford Crystal - a staff of 45, and a retail turnover in this country alone of a whopping pounds 37m. Later this week, Jasper Conran unveils his 2000 women's ready-to-wear collection at London Fashion Week - his 40th collection, neatly enough.
Despite this, however, Jasper Conran is more often than not portrayed as the golden boy, born with a silver spoon firmly wedged in his mouth, as, not to put too fine a point on it, a Conran brat. On the contrary, distressed by his parents' separation when he was only two, Jasper didn't speak until he was four years old.
"I own my own fairly substantial company. I'm in an enviable position. But it's taken me 20 years to get to this point. I'm a very serious businessman these days. I very much resent the concept of my still being a child. I mean, I'm not a child, I'm nearly 40, for God's sake."
Jasper Conran was born in London on 12 December 1959 the son of Superwoman Shirley and Terence Conran. When his parents divorced, Jasper was sent to live with his maternal grandmother, and later, aged seven, to boarding school at Bryanston.
"I suppose, I'm the product of a working woman," he says. "I didn't see very much of my mother. She didn't cook, she wasn't around. Now, you can't hold that against anybody but that was the truth of it. When I was at school, other people had mothers that did, well, the mother thing. My mother wasn't that. She just didn't go there. I always get this, you know: `You grew up in this family.' I didn't. I grew up at boarding school.
"Yeah, there was my father, and my stepmother (Caroline Conran) was fabulous to us. But it was always like being a visitor, it was difficult to know where I fitted in. I'm not complaining. But I think it was quite hard because I was forced to sail off by myself very early."
Aged 16, Conran went to New York, where he won a scholarship to study fashion at Parson's School of Design. "I kind of fell into fashion, really," he says. "I was interested in shape and in cloth, so I made the assumption that I was interested in fashion. In fact, what I was interested in was clothes, in structure and form. Fashion is just someone's whim. Fashion, to me, is too transient. I never like waste, and fashion is intrinsically wasteful. If I have a piece of clothing that I love, I wear it, and wear it."
It was a formula that worked. He returned to London to set up his business making glamorous womenswear - the perfect little black dress, say, or the softest leather jacket - that paid lip-service to passing trends without bowing down to them completely. And women loved him for it. He was successful at 18 and even more so at 20. Jasper Conran was a millionaire by the time he was 30.
The late Eighties hit the designer hard, however. Like many based in London at that time, he had been over-hyped and, as a result, had over- expanded. Jasper Conran's clothes were everywhere from London to the most up-scale, Uptown stores in Now York. There was barely a glossy magazine that didn't include his merchandise, his glamorous portrait or, at the very least, a razor-sharp Conran soundbite. Then came the crash.
"We had one American company after another going bankrupt - we were in every single one of them. They kept the clothes and we never saw the money. Sales plummeted, rent sky-rocketed. We were seriously stung. I would never want to go through that again."
If there is one thing that Conran will accept as having inherited from his parents it is his ability to bounce back. "I'm resilient. You know, you brush yourself down and start again, I think that's what maybe does run in my family."
In the mid-Nineties, Conran designed a collection of 10 black dresses. They sold in their thousands. Soon after he added leather and tailoring. At the same time, he was gradually re-employing his original members of staff. Since that time - and following a lucrative collaboration with Debenhams, in particular - the designer hasn't looked back. His renewed success is nothing if not testimony to the triumph of product over hype. Today, without fanfare, Jasper Conran's clothes sell phenomenally well, and for no other reason that women can't get enough of them.
"Obviously, I do get a little fed up when people say, `I've got this fabulous 10-year-old dress of yours which I still wear.' We are supposed to be a business. But then, it's also the nicest thing anyone could say to me. I try to make clothes that are user-friendly, clothes that become part of a woman's personality rather than my own."
Clothes that don't wear the wearer, I suggest. "Exactly," he says, "to use a hackneyed old phrase. My battle has always been against the concept of woman as dress-up-dolly, against woman as adjunct to man. When I started, that was what fashion was all about. It was about being tarty, dressing up for balls. Now women wear what they want, where they want, how they want."
Jasper Conran's aesthetic is more rigorous now than it used to be but it would be safe to say that he does, indeed, design precisely to suit women's requirements. In a climate where this is all too rare - our most feted designers are hardly famous for their consideration of such minor practicalities, for valuing the egos of their prospective customers over and above their own. Small wonder, then, that Conran's customers continue to be his greatest fans. After all, there are more than a few of us who would protest that this is just as it should be. 1Reuse content