IN THE theatre foyer, a tiny woman buying a jumbo packet of fruit pastilles is telling the usher how she remembers Jason Donovan in Neighbours as if it was, oh... no, really... only yesterday.
"Yes," says the usher, "but he looks a lot different now."
Don't we all. The usher is sporting a Mohawk haircut from 17 David Beckham hairstyles ago that would have been ludicrous in 1988 and isn't any more acceptable now.
I feel like telling him this, but he's being kind to the lady, showing her all the way to her seat, and today, in Manchester's Opera House, for a matinee performance of the musical Sweeney Todd starring the self-same former, not to say fallen, teen idol in the title role, her presence is welcome.
It's a small house, maybe only a couple of hundred, most of them OAPs, but in 1988 their age was no barrier to understanding Donovan's appeal, along with that of co-star Kylie Minogue, to 22 million Brits in the early days of daytime telly. The lovebirds, on screen and off, were the embodiment of young, confident, good-looking, "whotcha, mate" Australia. They were sun-kissed and far-off and exotic.
Then what happened? Oz youth migrated here, and somehow seemed less exotic when it started asking you if you wanted cheese and onion crisps with your lager on a raw winter's night. We still loved Kylie; some of us loved her bahookie more than anything. But then she got ill. That wasn't supposed to happen.
With Jase, the preoccupation for a while was with the hair: he was losing his. Then he got sick, too, although as he's quick to tell you, the frequent collapses - most notoriously in LA's Viper Room at Kate Moss's 21st - were entirely self-induced.
I'd read in unflattering profiles that the cocaine years - it was rumoured he snorted 250,000 worth - had taken their toll on Donovan's hunky, skater-dude features and, well, as that usher pointed out, he's not the boy he was.
But, lay off him. In fact, "Rack off, dag." Backstage after the show, he looks OK. The hair, what's left, is no longer blond. The eyes are hooded. But the face is still fairly youthful, so much so that the beard seems to be stuck on from a kid's disguise kit. And the handshake is still strong. And the sunshiney optimism has not completely deserted him.
"I don't regret a thing, that's such a waste of time," says Donovan, now 37. "There's no handbook on how to be a teen idol, and no sequel on what to do after your time is up. Once I did think about writing these books, back in one of my hazy, smoking moments..."
He sings OK, too. The Glasgow-bound Stephen Sondheim musical about the barbarous barber is not singalongy like his previous turns on stage, Joseph and the Amazing Technicolor Dreamcoat and Chitty Chitty Bang Bang. He calls it "art-driven" with fewer laughs, requiring proper singing. Donovan had to send his voice back to school.
"Stock, Aitken and Waterman were writing those hits as they went along and I was learning to sing the same way," he says. "Kylie had an instinctive ear, I had no studio experience. Long-term for me, that became a problem."
Did he feel like their puppet? "They were controlling to the point where they knew what they were doing... and I didn't." While he was helping flog 13 million records to teenyboppers, Donovan harboured a love that dare not speak its name: he adored rock. But he didn't rock the boat by asking SAW to make him sound like Kurt Cobain. "I understood Nirvana and Bananarama," he says. "And after a hard day as a teen idol I went home and strummed my guitar and smoked a spliff."
Over the years, there have been many theories as to why Donovan got into drugs. Hair-loss and Kylie-loss. Post-traumatic stress (caused by his mother walking out on the family when he was five) and pre-traumatic stress (over the impending end of his chart reign). And then there was his barney with The Face.
In 1991 he sued the magazine for printing a photo of him in a T-shirt with "Queer As F***" superimposed on top. He won the court battle but lost respect and was viewed as homophobic. Shortly after he turned down the role of a drag queen in The Adventures of Priscilla, Queen of the Desert, the part went to another ex-Ramsay Street resident, Guy Pearce, and the rest is Hollywood history.
That old one again: regrets? "People say I shouldn't have sued and maybe they're right. Maybe I'd have a nice little movie career like Guy's if I hadn't. But it [his 'outing'] was a violation of my human rights. I stood for something I believed in and over a period of time I think you gain respect for that, even though it puts a few more lines on your face." Has he ever questioned his sexuality? "Never, mate, never, never. And I'm a father now." Despite all those years in Pomland he's never lost his Melbourne accent, and now he's sounding very Australian, as if I've just grabbed his sausage off the barbie.
"But to come back to the drugs, are any of those things to blame? You guys are all amateur psychologists. Maybe all of them are. I also have to tell you that I wanted to have a bloody good time. I was doing Joseph, earning X amount of money, eight days a week, trapped in the Palladium, all the exits covered and I thought back to Neighbours and went: 'Uh-oh, here I go again.' I looked at a big poster of me in a loincloth and in that moment decided I didn't want to be the new Cliff Richard."
If Donovan was also seeking credibility through a dangerous lifestyle, at least now he's trying to gain recognition from challenging roles. After Sweeney Todd, he returns to his Melbourne to star in Festen, the stage version of the film of the family party of nightmares. Donovan plays the eldest son who serves up a shocking revelation with the after-dinner mints: that he and his twin sister were raped as children by their father.
"I'm looking for more challenging roles," he says. "For Sweeney Todd, a producer has taken a risk with me. But I'd like to think that all the dark stuff that's happened to me can help me as an actor, and maybe through Festen I'll finally get that interesting movie."
Here he checks himself. "Yes, I'm still ambitious, but do I need 20 rooms in my house? No." (He lives in a Notting Hill mews with his partner, theatre designer Angela Balloch, and their two children.)
The ever-frank Jason Donovan only declares two subjects off limits today: how much he's worth ("I never discuss it," says the canny property investor) and whether he's been in touch with Minogue since her treatment for cancer. "She's got good people around her, I'm sure she'll be OK," is all he says.
One other topic which usually draws a blank stare is the state of his (non-) relationship with his mother Sue, a TV newsreader in Australia. But today he reveals they've recently been in touch for the first time in years and soon he hopes she'll finally be introduced to her grandchildren.
Life, he says, is too short - and too precious. "Eventually, even one-time teen idols are struck by feelings of mortality." Then, digging deep, he summons up one of those smiles that once made you think the sun was going to blaze down forever.
• Sweeney Todd, Theatre Royal, Glasgow (0141-240 1133), March 20-25