Stars are supposed to be stars because they're not like us. They're our escape from reality. But now suddenly Big Brother, You're A Star, Jerry Springer, blogs and YouTube are reversing the celebrity equation. The public increasingly demands that stars should be just like us. Forget about talent or intelligence. All that's needed for absolutely anyone is just a bit of luck. It's what Andy Warhol referred to as being famous for 15 minutes.
Take the case of the staggering box-office success of Mamma Mia! the big-screen version of the West End hit musical. Despite decidedly mixed reviews – the Guardian critic complained that it made him "need to vomit", Pierce Brosnan's singing was likened to "a donkey braying" – audiences adore it. Already, its grosses have topped $475m, which includes more than $10m in Ireland.
And what's remarkable about Mamma Mia! is its lack of synthetic Hollywood musical glitz. Ask Colin Firth, who improbably stars as one of three men – the other two are Pierce Brosnan and Stellan Skarsgård – invited to a Greek island to be vetted by the 20-year-old daughter of single mom Meryl Streep who thinks one of them may be her father.
"It's a hit because it's not slick," he says. "Unlike Hairspray, where one of the things you're enjoying is the brilliance of the dancing and the singing, which was all first-rate, this is not true of Mamma Mia! Meryl Streep can sing as well as anybody, but a lot of the cast – like me – couldn't sing if their life depended on it. That's the whole point of it. Nobody minds. It makes it accessible. It thrives on being amateur."
That's why people are still packing out the stage version. "It depends on the feeling of just being there. You're part of the hen party with everyone else. You're a curmudgeon if you don't get up and dance. It reels you in. Getting that exuberance to work in the same way on celluloid without a live presence was no shoo-in, but somehow it does. It's a very personal project for the people involved. It wasn't handed over to a hired hack from Hollywood. It has the same director, producer and writer. So it's from the heart."
Initially, though, Firth was sceptical. "I couldn't make head or tail of the script. I didn't know what it was about. I mean, you just try reading a script that's largely made up of Abba lyrics. Whatever their value or whatever you think about them, they don't make great coherent reading in terms of drama or dialogue of any kind. I got to the end of it without having a clue what it was. I had to go and see the show to get any idea at all. I'm still a little confused, even after seeing the film."
He took the part "because it seemed such a silly idea, it was irresistible. It seemed like a party was being given and it would have been a pity to miss it. It's brilliant that there are films like this and that they work, sometimes. There's a kind of exuberance to it you don't often find in cinema. I'm glad we don't just live in a world of Fassbinder films."
Although Firth made his stage debut with Kenneth Branagh in the award-winning 1983 London stage production of Another Country, and has shown a serious side in The English Patient, A Month in the Country and Girl With a Pearl Earring, he's always had a flair for the popular. Playing Mr Darcy in the 1995 television adaptation of Pride and Prejudice made him a heartthrob, an image enhanced by his comic reprise as a latter-day Darcy lusted after by Bridget Jones in film versions of the Helen Fielding novels. He's cleverly translated this success into Hollywood bankability with variations of a harassed Englishman abroad role, whether in Atom Egoyan's Where The Truth Lies, What a Girl Wants or as an embittered single dad in Helen Hunt's directorial debut Then She Found Me.
Not that it's been deliberate. "Every time I've been in an American film, I've offered my services as an American, but they preferred me English. If there's more texture to be found in a story by my Englishness, that's fine. It raises the stakes a little if you're playing someone who's lonely and damaged to put them in an environment that is not their own."
When Atom Egoyan cast him with Kevin Bacon as a 1950s cabaret double act in Where the Truth Lies, Firth suggested modelling his character on Dean Martin. Egoyan wanted a second-rate Noel Coward. "You use the baggage you've got. An Italian-American beating the crap out of a heckler wouldn't be surprising. But an Englishman, all manners, who goes backstage and beats the crap out of someone, that's upsetting. So you play with the stereotype."
That's why the low-budget Then She Found Me hooked him. "It's not a Lord Snooty in Hollywood thing. It's not written with whoops-a-daisy dialogue. I like messed-up characters. I can't think of an interesting film about someone having an easy time. Life isn't easy for Hamlet or Romeo and Juliet. A character has got to have some obstacles."
Firth by now is arguably as American as he is English, if indeed he belongs anywhere. His mother and father both grew up in India, where their parents were missionaries. Although he was born in Hampshire, much of his childhood was abroad. "I was nearly four years in Nigeria, another year in Missouri. A lot of my adult life has been lived in North America. I've a son – by Meg Tilly – who grew up in the States and Canada. I now have an Italian wife – director Livia Giuggioli – and have learned Italian so I can be a more convincing partner and father to our sons Luca and Matteo. Nobody knew that when they wrote the part I played in Love Actually, where something similar happens. It seems life does imitate art."
While filming Mamma Mia! he also did Genova with Michael Winterbottom and shot a documentary with his wife about a death row case in the US. "A lot of it had to do with racial tension and how we don't really get the sort of rhetoric we used to hear from Martin Luther King. Most of it seems to have gone into rap. I remember a week in which I kissed Rupert Everett, interviewed Snoop Dog in Amsterdam, returned to Michael's film – which is to do with a death in a family and a single father raising his daughters – and after that I was back in spandex and lycra for an Abba number."
He's just finished Robert Zemeckis' motion-capture A Christmas Carol with Jim Carrey and will star with Ben Barnes (Prince Caspian) in Dorian Gray, a retelling of the Oscar Wilde classic about a hedonistic man who stays eternally young, but whose portrait ages horribly. "Mamma Mia! it isn't," he says. "Acting is a nebulous craft. People don't quite believe that it's a craft at all. A lot of people think it's just mincing about. You can't talk about it without sounding like a prat."
'Then She Found Me' and 'Mamma Mia!'
are currently on release