We’ve spoken a few times since, but then we drifted. Well, I say we. I stayed put, while Hilton morphed from D-list cutie to A-list megastar. All of a sudden, she had a television show, a book deal, a record contract and, before long, perfumes, handbags, sunglasses and lingerie all bore her legend. A former boyfriend released a video of their pedestrian lovemaking (1 Night in Paris), Camille Paglia weighed in on her cultural significance and Hilton joined that cast of ghouls who feature weekly in Heat magazine. But where was that warm, witty girl who always made a point of emptying the dishwasher? She’d gone — apparently replaced with a dumb sex maniac who loves going down on camera before heading out to bitch-slap some rival skinny girl in the club toilets.

We meet again on a balcony at the Sanderson hotel, surrounded by fashion shrubbery, with Hilton, 25, in a floor-length ball gown and outsize white-rimmed sunglasses. My first question is, what happened? “I know, right?” she giggles. “Things got, huge.” And you let them? “Yes, I did.” But why? “Because there’s nobody in the world like me,” she says, smiling lazily. “I think every decade has an iconic blonde — like Marilyn Monroe or Princess Diana — and right now, I’m that icon.”

For better or worse, she is right. Last year, the author Naomi Wolf was quoted as saying Hilton is “an empty signifier you can project anything onto” — but she was wrong. To fans and haters alike, Hilton signifies the base desires of the age: money, sex and low body fat. So the interesting question is not why she fascinates us (we’re shallow), but how much her public persona matches her private self. I know for a fact that the airhead sauce-pot people love to hate is, at least in part, a creation. Because while teens are busy buying her perfume, sleazebags watching her fornicate online and intellectuals debating her worth, Hilton is making a second fortune. Forbes magazine estimated her earnings last year at £4m. Soon, her business profits will have eclipsed the inheritance on which the whole fantasy about her hinges, a sum she has to share with multiple other grandchildren, and which, though impressive, would never have landed her in the Sunday Times Rich List.

“There’s a lot of heiresses out there,” she says, “and I don’t see any of them doing what I’ve done. It’s Paris Hilton plc, baby! I have so many projects — bags, fragrances, make-up. I go round the world every three days, designing and personally approving it all. I’ve got movies to make, a tour, TV shows. Every day of my life is scheduled until the end of 2007.”

It’s a more frantic existence than the one she was born to. As a child, Hilton — whose great-grandfather was Conrad Hilton — lived at the Waldorf-Astoria in New York, but struggled academically (and socially) at a series of posh schools. Her fate was to laze around various mansions waiting to marry someone even richer than herself. “But I was never that kind of girl,” she says. “I was having dinner with my grandfather last week, and he said, ‘You work harder than any CEO I know.’”

Hilton is currently doing a spin-off of her show, The Simple Life, for £1.6m and earning millions more endorsing products in Japan. “There’s nobody who can generate as much as I can for events either,” she says. “They did a poll in the States asking people who they’d most like to see at a party — and it was me.” She has been paid as much as $1m for a 20-minute appearance at a nightclub. Granted, she is helped by a team of advisers, but she hand-picks them. The overall Svengali is Hilton herself: “I’m the boss and I love it,” she says. The latest addition to the brand is music. When we lived together, she used to sing along to dreadful tunes on a candy-pink Discman. Lucky by Britney Spears, Bette Davis Eyes by Kim Carnes and the like. I feared the worst when I popped her new CD into my stereo, but it’s mostly great and will doubtless reel in even more cash.

But is she paying too high a price for success? The real Hilton (funny, sweet-natured) has become a stranger to all but her friends and family. “I read these stories about me starting fights and saying stupid stuff. I’ve become a cartoon. Nobody seems to get that how I am on The Simple Life is a character. I even know what a Wal-Mart is (on the show, she asked: ‘Do they, like, make walls there?’). I play dumb like Jessica Simpson plays dumb. But we know exactly what we’re doing. We’re smart blondes.”

If she’s going to scandalise feminists by playing the ditz, I suggest she could at least stop scrapping with other girls. It’s so undignified. “All those stories are made up. You know how shy I am.” Rubbish. “Okay,” she laughs, “but I’m non-confrontational. Certain girls just use me to get media attention. They have their publicists call the tabloids and make something up, because a feud with Paris Hilton always gets press.”

Who are these girls? “I read about one in Britain the other day,” she snorts. “This girl (I think she means Frank Lampard’s girlfriend, Elen Rives) talking like I dissed her. I don’t even know who she is.” Then you tore a strip off Lindsay Lohan because she was getting too close to Stavros Niarchos, your ex? “That was crap. She’s never even hung out with Stavros. He thinks she’s pathetic.” In fact, Hilton rarely starts the fight. Years ago, before she was famous, I’d watch as complete strangers gave her evils in the street. Maybe she just has a slappable face? Her opinion is that “jealousy is a terrible thing”, also the title of a song on her album, which details the breakdown of her friendship with her fellow celebutante Nicole Richie. “I was crying when I wrote that,” she says. Is Nicole jealous of you? “I don’t really want to say that, but ... ”

Well, if you’re not dumb and you don’t pick fights, at least admit you’re a nympho? “No, I’m a romantic,” she laughs, “and let me tell you, it’s really exhausting being a girlfriend. I’m always putting all my energy into some guy and I’m bored with it. I’m tired of thinking about men.” Hilton’s men fall into three categories: fellow heirs, hunky models and downright SOBs. The first speaks of her elite upbringing and desire to marry well, the second of the fact that she prizes physical attractiveness, and the third? Well, every girl loves a bad boy — and boy, can she pick them: Edward Furlong (ex-druggie), Nick Carter (buffoon), though neither was as bad as Rick Salomon, who captured 19-year-old Hilton in grainy night vision, performing assorted sex acts. In 2003, the video “leaked” online and doubled Hilton’s fame overnight. “He did it to ruin my life, but I’ve only become stronger.” So there was an upside? “There was no upside. It was the most horrible thing anyone’s ever done to me. It was humiliating. I have to live with it for the rest of my life.” Hilton did, however, sue Salomon successfully for £220,000, and to this day receives a percentage of the tape’s profits.

Your problem, I say, recalling her obsessive relationship with Jason Shaw, the model, is that you fall in love too fast and too hard. “I know. It’s always getting me into trouble.” Is that why you and Paris Latsis, the Greek shipping scion, got engaged and broke up in a matter of months last year? “Maybe, but whatever. We’re better as friends. I wasn’t ready to get married. I’m not going to have a boyfriend for one year,” she boasts. That won’t last. “We’ll see. I definitely want to have children at 30.”

I remind her of the time she dragged me off a dancefloor to explain how sick she was of the celebrity merry-go-round and had decided to get shacked up and pregnant within the year. “I know,” she says, a bit sadly, “but I have to make the most of things right now. I’m stuck in the myth, baby.”

Is it tough? “It can be. Sometimes I feel like the media uses me as a punchbag.” What did you expect? “I know, but it doesn’t stop it being lame. But I love my job, and I think I’ve earned the right to be happy now. God gives you good karma if you work hard and play nice.” You’re religious? “Yes, Catholic.” Do you keep a Bible by your bed? “No.” Just a camcorder? At this, the smart blonde flicks her hair and deadpans, “Whatever, man. At least I’ll always be remembered.”

Paris Hilton’s single Stars are Blind is out on July 31 (Warner Bros)

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