At an age when most people have barely begun thinking about what to do with their lives, Clare Grogan had already done it all. In the late autumn of 1979, with the bright hope of a new decade about to dawn over a tired and gloomy Glasgow, she was just 17 and waitressing in the now long-gone Spaghetti Factory restaurant in Gibson Street. There, Grogan was talent-spotted by the one-man Scottish film industry that was Bill Forsyth. The result was her starring in Forsyth's beloved Cumbernauld-set comedy Gregory's Girl. Its phenomenal success was thanks, in no small part, to Grogan's turn as the lassie who steals John Gordon Sinclair's heart with a compelling mix of too-cool-for-school sussedness and naive coquettishness. It made her a star overnight.
That was a lucky break, but Grogan's precocious rise to fame was no accident. By the time she began working with Forsyth, she was already plotting a parallel course out of her childhood home of Garnethill and on to the stage of Top Of The Pops by fronting Altered Images, a wee school band with big ideas that caught the attention of their post-punk, new wave heroes Siouxsie And The Banshees (bassist Steve Severin agreed to produce their first record). For a few short years, fresh-faced and squeaky-voiced Grogan was the Lulu of her generation, with pouting lips and ribbons in her hair, whirling and spinning on top of a world of limitless possibilities.
"It still amazes me that it happened," says Grogan now, as she settles back into an armchair in the Centre for Contemporary Arts on Glasgow's Sauchiehall Street. The past quarter-century has aged her, but not unkindly. The impish pout is still there, as is the twinkle in her eye. Her hair is in a neat blonde bob with not a ribbon or dangly ear-ring in sight; the jeans, muted top and designer bag complete the look of a mature, stylish career woman in her mid-40s. Now an avowedly contented jobbing actress and occasional TV presenter, she projects an image that has altered almost beyond recognition since she sang the nursery-rhyme smash hit Happy Birthday to audiences of millions in 1981.
"When I look back it's almost like looking at a different person," she says. "I never used to be sentimental about it, but now I have wee moments of thinking: that was me. I did that'. And it's odd, but nice."
Youth and innocence have defined Grogan's career. "In the early days of Altered Images we really were schoolkids," she says. "And I think nobody wanted to corrupt us. We were hanging out with the Banshees and The Cure and it was kind of crazy - but in a manageable way. I wasn't so much frightened of drugs, I was frightened of my mum and dad finding out. And that kept me safe for a very long time. It still does. I have had my moments of craziness, but they are deep down." She pauses: "I just like drinking!"
Eschewing drugs in favour the drink is one of several stereotypically Scottish characteristics Grogan attributes to herself, along with an innate socialism, bolshiness and a love of her native city. She currently divides her time between her own house in Haringey, London, and her parents' in Glasgow. (This visit north is specifically to see her mother, who has taken ill and is currently being cared for in hospital.) The need to be close to her family and friends, to her country, to her sense of roots and of "real" life, has had a fundamental bearing on the career decisions Grogan has made, for better and worse. Indeed, it was fear of losing the things most precious to her that prompted pangs of doubt - and even guilt - when that first burst of fame accelerated into a full-on, jet-set existence all those years ago.
"When I was young and flying all over the world, meeting Hollywood producers and basically living the dream, it just didn't work for me," she says with a pained expression. "I could bluff it brilliantly, but beyond a certain point, I thought: I can't pretend to be someone I'm not'. I think I was really fortunate to recognise that in myself at an early age. I knew I wouldn't walk away completely from it, but I used to sit in the Beverly Wiltshire Hotel in Hollywood and wish I was back in The Rock Garden in Glasgow with my pals. My life had become, unintentionally, very different from the people I really cared about and I wasn't comfortable with that. It made me feel quite isolated. And I had a hunch that I would never get over that feeling."
The problem was solved when personal stresses within Altered Images, along with the disappointing reception to their 1983 album Bite, caused the group to disband. "I got on really really well with the boys, but like any group of people living in each other's pockets, eventually you niggle. Being the only girl, it did feel like the boys were having to take their wee sister everywhere with them." Grogan maintains that, following a reflective year out in Glasgow in the wake of another successful collaboration with Forsyth for the film Comfort And Joy in 1984, she then walked away from pop music completely because she realised she lacked the single-minded ambition required to be a successful solo artist.
Cynics would say the decision was actually made for her when an attempt at a solo career in 1987 turned into an ignominious flop. An album recorded with Madonna's then-producer never saw the light of day.
But Grogan is sanguine about it. "When you're young you think everything will last for ever. Even after I left the band, even though part of me didn't really want it to continue, I thought I could just pick up where I left off and recreate all the magic again. But you can't. One single came out. It was called Lovebomb - and bomb was definitely the operative word. The world had moved on."
Grogan had to move with it. Still only 25, there was no option but to find new challenges. "I think I was really fortunate not to have made lots of money when I went solo. Because it forced me into a position where I had to earn a living. And I come from a very typical working-class Scottish background where that's your option in life - to get a job."
The end of her music career (notwithstanding recent 1980s reunion tours with the likes of T'Pau) also removed a destructive tension between the different demands of singing and dancing. "There was a conflict of interests and you get to the point where you're just trying to keep everybody happy, but you are the unhappy person in the middle of it."
Acting became her sole focus, but she remained forever Gregory's Girl to many people, who had difficulty accepting her as anything other than versions of that character. There have been memorable roles in popular TV shows, however. At the turn of the of the 1990s, she played lusty starship officer Kristine Kochanski in Red Dwarf (which still accounts for a disproportionate amount of her fanmail). In 1998, she also played Ian Beale's love interest in EastEnders.
Yet in spite of some additional successes on stage, Grogan has never been able to completely flit the shadow of her early work. Even now, starring in the sporadically hilarious BBC Scotland comedy series Legit - centred on two ne'er-do-weel Glasgow flea market traders - her role as an over-sexed (and sexy) mum flashes a knowing wink at the nation's collective memory of the kitten this tigress once was.
Grogan has learned to live with, and even be grateful for, the elephant that never fails to turn up in the casting room. "It really bugged me in my early 30s, when I was trying to move on, but now I think, isn't it wonderful that people remember me at all? Some people think I must miss the glory days of Gregory's Girl, but I so don't. I have got frustrated now and then, but if I'm being brutally frank, the lowest points in my life have not been career-related."
Although it hurt when she was ditched by the producers of Red Dwarf for being "too old" at 31, and she still kicks herself for turning down prestigious TV projects in the US because she couldn't bear to live so far away from home, there have been much harder blows to deal with. "Your career panning out not quite the way you thought it would, well that's life. But not being able to have children, that has been difficult."
In 1994, Grogan married Stephen Lironi, a former bandmate and successful record producer. The impression given is of a happy, secure marriage, but one tinged with sadness at Grogan's inability to conceive.
"I had a series of miscarriages through my 30s," she says quietly. "They never found out what the problem was. Then I went through IVF and I became one of those women who has this big biological clock ticking inside me that I had to do something about. So I felt really compelled to explore every avenue of it. And then finally had this enlightening moment when I thought, actually, why don't you just try some different thinking here?"
That different line of thinking was adoption. After a chance meeting with a friend who had taken on an adopted son, Grogan felt something inside her click. "I thought, why didn't I do this before?" After a period of soul-searching and seeking professional advice, she and her husband realised it was what they both wanted, and took steps to adopt their baby, Lucia. That was two years ago.
"When you adopt a child they encourage you to stay off work for a year so you can make that connection, that bond, which I was very happy to do," she says. "But after that I realised, I would like to do a wee bit of work as well. I've become one of those work-and-home-juggling mums, which is exhausting, but it's OK.
"We have both had to make adjustments, but thankfully Stephen is hopelessly in love with his daughter, which has been really great for him too. This has got him out of the studio, so that's been really nice for all of us.
"Everybody has their own wee area of shite to deal with, and for us it was not being able to have children. But we got our happy ending. It's hard not to sound really corny about it, but it just makes perfect sense."
There seems no good reason to avoid sharing Grogan's conclusion that she has found a happy ending to the first half of her life; allowing her to open up a new phase as a parent and an established career actor.
"My life now is not all popcorn and candy floss, but it's a real life. I don't want to anaesthetise myself to what's really going on. I never have and I never will. You hear things like Brian Ferry has never been to a post office and doesn't know how to pay the gas bill. I'm not interested in ending up like that."
But, reassuringly, the new and mature Grogan retains more pop-star whimsy than she realises. As she prepares to visit Lucia's grandma in hospital, she points through the glass doors to the whizzing thoroughfare of Sauchiehall Street and asks, with just a flicker of teenage naivety: "Do you think I'll be able to hail a cab out there?" Suitably reassured on the subject, she steps out on to the pavement. Proud former pop star. Contended jobbing actress. Loving wife and mum. It seems Gregory's Girl has finally grown up.
Legit is on BBC One Scotland on Fridays at 9.30pm