Chanel’s new shop on 57th Street is a hotspot for New York fashionistas. But if you ever wanted to fix a pivotal point in the whirling, uncertainly balanced wheel of fashion, you might choose the Chanel headquarters on rue Cambon in Paris. For this is where Coco Chanel – or, as she is known here, Mademoiselle Herself – established an empire that continues to flourish.

Now, on the afternoon (which will be stretched into the night) before the latest Chanel show, Mademoiselle’s studio is filled with a bewildering number of people. Rising above the chatter, a song can be heard, playing from the soundtrack prepared for the new collection. “This is not a love song” croons a girl’s voice.

Overlooking this activity is a portrait of Coco Chanel, and her eyes seem to be watching her successor, Karl Lagerfeld, whose arrival in 1982 set in motion an inventive series of collections that have been both loved and hated – which is a measure of success in a world where boredom is a cardinal sin. If you want exact figures to prove this point, they’re hard to come by (Chanel is privately owned, though it has recently confirmed that sales in its fashion division were up 38% in the first half of this year).

At 66 years old, Mr. Lagerfeld is slim – famously so after a diet in which he lost 90 pounds and gained a new wardrobe, made by his friend Hedi Slimane, the designer of Dior Homme. This afternoon, he is wearing an iridescent maroon jacket, a high-collared, immaculately tailored white shirt, tight gray-black jeans, his trademark dark glasses and silvery hair in a ponytail.

“Oui, c’est jolie,” says Mr. Lagerfeld, picking through a box of fabric camellias to attach to the beret of a 16-year-old model. “This is great, non?”

He speaks very fast, in a swirl of languages, as befits a man fluent in French, English, and Italian. As to his own nationality – German – he has in the past preferred to describe himself as “old European.”

His latest edict is that “there is no in-between any more. I believe in extremes – Chanel and H&M,very expensive and very cheap.” He has just designed a small collection for H &M (“just 30 pieces,” he says, “very androgynous”), which is likely to sell out within a few days of its release in November, so eagerly is it anticipated by the fashion press.

Aside from this, he is also juggling deadlines for Fendi and his personal label, Lagerfeld Gallery, not to mention his publishing company, 7L, his bookshop and his photography. “I don’t consider it work,” he says. “Work is existing in a factory – I don’t work.”

When I comment on his rings – from a Californian company, Chrome Hearts, all but obscuring a signet ring that belonged to his mother – I ask why there are none on his middle fingers. “Not today, but tomorrow, huh?” he says. “Who was it that sang ‘Tomorrow May Never Happen’? An English song, by the girl who was killed in a car accident. Very sweet. I like that song. Tomorrow may never come. That’s why people buy clothes – let’s wear them today.”

You might wonder why a man born in Germany in 1938 has chanced upon a theme tune so different in message to one more often associated with that era, “Tomorrow Belongs To Me.” His father, a Swedish industrialist who had made a fortune out of a condensed-milk business, was 60 when Karl was born, his German mother 42. Karl was the only son, treated almost as an only child, he says, with a much older half-sister from his father’s first marriage, and another older sister from the second.

Interestingly, you get the sense that his parents might be closer at hand these days, as powerful, if ghostly, presences in his life. He tells me that his best design ideas appear in dreams – “I have very clear visions of what I want to do, what I should do, what I could do” – but also, “I have nightmares too, that I prefer not to talk about.” Mr. Lagerfeld is clearly a man with no time for analysis, but what could be made of his admission that in his dreams he hears only the voices of the dead, “never those who are alive”?

His hands flutter slightly as he talks, though his voice is gentle, as ever. “I just had a dream which was very funny,” he continues. “My father died over 30 years ago, but I dreamt I was in his boardroom with him, and a lot of people who I didn’t really know; I didn’t know their faces, because I never worked with my father. And then they served lunch, and my father said to me, “You can’t have lunch because you don’t know how to use the PowerBook. You won’t eat until you learn how to use it.” My father died long before the PowerBook computer was invented, of course, but it was him, it was his voice, the way he dressed, the paneling in the boardroom, everything was there, exactly as I had seen as a child.”

As for those other ghosts in his life: Well, there is his mother, who sounds sufficiently imperious in life to remain a powerful figure in death.

Much of how Mr. Lagerfeld presents himself to the world today can still be attributed to her: He speaks fast, because she told him that otherwise she would not listen; he does not smoke, because she decreed that his hands were too ugly to draw attention to; he is multilingual, because there was no other way to follow her conversation. “I always wanted to be a grown-up person,” he says, “because my mother said that children were stupid.”

She sounds terrifying, I say.

“No, no, she was perfect for me,” he says, “and she was always right. It was a good thing for me to try to speak like a grown-up person. She would tell me, ‘You are 6, but I am not, so make an effort.'”

And so he did make great efforts. “By 5 years old I could read English and Spanish. My father didn’t like to speak German, he spoke mostly English.” Now he is thin, he says, he could fit into a Chanel tweed jacket; but he has only tried this once, because when he looked at himself in the mirror, he could see the reflection of his mother, which frightened him.

She is buried in the private chapel at the house he inherited from her in Brittany; so, too, is Jacques de Bascher, Mr. Lagerfeld’s closest friend for nearly 20 years, who died of AIDS in 1989.

Even before that loss, Mr. Lagerfeld has never veered from being, essentially, solitary; he did not share a house with de Bascher, nor has he done so with anyone subsequently. True, he has his retinue: Eric Wright, his right-hand man at Fendi, who has worked with him for 25 years; Amanda Harlech, his muse at Chanel, and Mr. Slimane.

“But I nearly never go out,” he says. “I am not glamorous at all. I stay in, because otherwise there is not enough time to do everything.” And at the end of the day, he goes to bed alone – a small single bed, the same one that he had as a child.

He seems to be a man seamlessly himself – which is odd, given that fashion is based on change. And of course, Mr. Lagerfeld has changed, not only in his reshaping of his body, but earlier, because he surely was not born into the world wearing dark glasses.

At 14, he left his birthplace of Hamburg to study in Paris, and changed his name from Lagerfelt. Two years later, he won a prize from the International Wool Secretariat for designing a coat; a teenage Yves Saint Laurent won the dress prize, which may have been the beginning of what turned into a lengthier competition between the two.

Soon afterwards, Mr. Lagerfeld was hired as an assistant by Pierre Balmain, then one of the grandest of French designers, and at 21, he became artistic director of the couture house Patou. From Patou, he was commissioned to create a luxury ready-to-wear line for Chloe, thereafter adding Fendi to his clients; so that by the time he joined Chanel, 22 years ago, he was already famous, rich, and confident in his ability to confront that most challenging of ghosts, Mademoiselle Herself. “I took her code, her language, and mixed it all up,” he says.

At first, his reinventions horrified the purists. But he could never be accused of being dull, never held to account for the slowness that his mother so despised.

Despite Mr. Lagerfeld’s admirable breadth of knowledge, he is unwilling to intellectualize what he does. “I am very superficial,” he says, gesturing towards a model. “I think these are just clothes, no great theories behind it.” He is equally pragmatic about his own appearance. “You know, I put on weight, because for 10 years fashion was boring, and then suddenly something appeared that I wanted to wear.”

The truth, perhaps, is a bit more complicated, because part of Mr. Lagerfeld’s act is to make his conjuring tricks seem effortless. Houdinilike, he has escaped out of his fat-suit, and thrown away that signature fan of his, that seemed partly a shield. “I think I don’t need a wall anymore between myself and the world,” Mr. Lagerfeld says.

He has also divested himself of other evidence of the past, selling much of his art collection. “At the moment I want nothing,” he says. “I like houses with space and light.” He has a new house, too, which he is planning to remake: a castle in Champagne, the Chateau de l’Isle. There, he tells me, he wants a garden just like that in “The Others,” which is one of his favorite films. “The Others” is a ghost story seemingly set in the 1940s, but where time has turned in on itself: The dead are haunted by the living, as well as the other way round and a house is surrounded by a misty garden that seems a kind of limbo.

When I see him the following evening, I wish I could ask him more about his island castle; but I can’t get close enough. The collection has been shown on a cruise boat: strict blazers with clouds of tulle and chiffon, silvery sequins against rough tweed, as we all go sailing down the Seine. But now the voyage has returned to the place it started from, and I am back on land again, amid an audience chirruping about the triumph of the show. Mr. Lagerfeld remains on board, separated from us by the river water, standing on the top deck, still wearing his dark glasses, of course, so I can’t tell what he’s looking at and his head is tilted upwards, at an unseen something in the darkening blue sky.