It was 2000, and I was in Addis Ababa with the actor Rupert Everett, reporting on a trip he was making with Oxfam to raise awareness of the plight of millions of starving Ethiopians. Everett was standing next to a patisserie counter in the Sheraton Hotel when - as I wrote afterwards - "he made a tongue-in-cheek reference to the bizarre juxtaposition of these two worlds ... With a sweeping gesture of the hand in a menacingly affable way, he beckoned governments to 'let them eat cake'."
They say irony never works in newspapers, and sure enough when the piece appeared (in the Times Saturday magazine), Everett's "let them eat cake" line was used in a caption in a way that suggested he really was a latter-day Marie-Antoinette. These things happen, and those concerned usually forget about it. But it clearly rankled with Everett.
The actor has just published a highly entertaining autobiography, Red Carpets and Other Banana Skins, now riding high in the best-seller lists, and it includes a chapter devoted to his Ethiopian visit. The "misquoting" wasn't the half of it. "It was a disastrous trip," Everett writes, "confirming what I'd always suspected. Maybe I just wasn't cut out for charity work. They (the Oxfam staff) all drove me mad with their piousness, and they couldn't stand me."
But it's the section in which he writes about me, the PR, and the photographer who came with us that really caught my eye, and which raised questions about this particular journalistic sub-genre. Leaving aside the matter of Everett referring to me quite wrongly as the daughter of the King of Romania, he has a go at both the photographer - to whom Everett had been very rude during the trip - and the PR. Of her, he writes: "If she had meant for me to seem less selfish, to give a saintly hue to my public persona, she couldn't have failed more dismally."
This wasn't how it was supposed to turn out of course - at least as far as Everett was concerned. I've been on numerous celebrity charity trips - to South Africa with Helen Mirren, to Tanzania with Susan Sarandon, to Laos with Richard Wilson, to China with Alan Titchmarsh, to Mali with Katherine Hamnett - and everyone involved always has their own agenda. There's nothing wrong with that. But as you turn up in your Jeep and drive down a dirt track into another blighted community where the villagers swarm out of their homes hoping you are their salvation, the question that the celebrity, the charity worker and the journalist must all ask themselves is, will these people's lives improve because I am here?
The answer, I believe, is yes- but not immediately and perhaps not to those people specifically. Money is donated to programmes, awareness is raised, and readers start to think of Ethiopia or Laos or Brazil as more than just holiday destination. The process can be fraught though, and you only have to look at the furore surrounding Madonna's adoption of a baby from Malawi to see just how problematic can be the mix of celebrity and the developing world.
Everett found it excruciating that the photographer wanted to take pictures of him next to famine victims. I recall Katharine Hamnett losing her temper with a charity worker who sought a photo opportunity from her as she was handing over a gift of two large bags of salt to a village elder in Mali. Being taken for Lady Bountiful or a celebrity do-gooder was her worst nightmare. "I'm sorry but I'm not here for some crappy PR thing," she said bluntly.
No one likes the idea of it all being "a crappy PR thing", and as a journalist I have always tried to write less about the celebrity than about the issues that their trip is raising. I chose not to describe how one high-profile model I travelled with to an earthquake zone would wander off leaving someone in mid-sentence whose entire world had been destroyed.
But one can't be too high-minded. As a journalist, you always hope that by getting up close and personal with the celebrity - enmeshed in conversation during bumpy internal flights, stuck in cars for hours on end, bleary-eyed over a beer late at night - you'll uncover some gem about their personal life. Mostly it's minutiae. I've discovered that Helen Mirren loves a bargain, Richard Wilson mixes cold baked beans with his lettuce, and that Katharine Hamnett is too much of a "truth-teller" to make a good mistress.
There can be tensions. There were with Helen Mirren. She has done advocacy work for Oxfam for more than seven years (often away from the eyes of the press), and I admire her greatly. But on a trip to Uganda with her, she became irritated with me when I kept asking former child soldiers and girl sex slaves for details of what they had endured. Mirren thought I was being unnecessarily intrusive. I believed I needed the evidence for a story that would shake the reader.
I liked writing about Rupert Everett because he didn't censor himself and he was tenacious. He made us all think. Colin Firth was similar. On a trip highlighting fair trade, he kept questioning how celebrity could be used to make a noise without trivialising the issues. But Everett asked the most provocative question of all: does aid actually work?
There was another side to him too. He wasn't precious about his reputation. In his autobiography, he jokingly refers to the moment when his PR phoned to suggest he did the Oxfam trip: "Darling, I was wondering, do you think you're becoming a tiny bit selfish?" Selfish or not, Everett was the only celebrity I have ever travelled with who didn't ask to check the copy. Perhaps he regretted that.
Red Carpets and Other Banana Skins by Rupert Everett is published by Little, Brown at £18.99