If Shortland Street were an actual rather than a virtual New Zealander, it could now vote, go to war, and buy a beer. Yep, our homegrown soap is turning 18. The cake gets cut on Tuesday.

In a way, it seems just yesterday the infamous line "You're not in Guatemala now, Dr Ropata" was uttered. Yet it also feels an age since we stopped relying on foreign imports for our soap fix. Over the past 18 years, Shortland Street has became a talent incubator for actors, writers and directors, paved the way for local series such as Outrageous Fortune, and entrenched itself in our popular culture, stirring up debate about topical issues, from gay relationships through to vaccination.

There from word go has been Michael Galvin, 44, who plays the ageless Dr Chris Warner. At 14 years in service (punctuated by a four-year stint overseas), he is Shortie's longest-serving cast member and its patriarch.

Back in 1992, though, a 26-year-old Galvin didn't think Shortland Street would make its first birthday, let alone its 18th. "The first segment rated through the roof because TVNZ had promoted the heck out of it and everyone tuned in to see what all the fuss was about. Then they tuned out."

To call those first few shows green, wooden or cringe-worthy would be an understatement. "But soon it got better," argues Galvin. "More people started watching, then about six months in we were flying."

Yes, he has rewatched those early episodes on TVNZ 6. "I expected it to be shocking, and it's only occasionally shocking - a lot of the time it's good. The weird thing is there are no sound effects and the sets are very flat.

"The thing that's changed the most is the production values. They're much better now."

The show's certainly much slicker, but many things have stayed the same. Like flatting, sleeping and socialising only with your workmates; lightning-speed hook-ups, break-ups and rebounds; and Chris' quiff. "And what the show set out to do - reflect New Zealand society - that hasn't changed," adds Galvin.

Neither has the scientifically worked-out balance of characters. "You could go back to the first week and go, 'well the equivalent to that character is this one'." Take the succession of mumsy receptionists (Marj, Moira, Barb, Yvonne), suave CEOs (Michael McKenna, Chris, Callum), or hot, party-girl nurses (Tiffany, Toni, Alice, Frankie).

One thing that has stayed the same is Chris' lady loves. They're always around, but there's a revolving-door policy. With four wives, various engagements, numerous girlfriends, affairs and flings, "Dr Love" has left a trail of bombshells.

"Yeah, there've been some great ladies," Galvin grins, imitating a playboy-like drawl. So many, in fact, that the Shortland Street publicity department emails through a file titled "Chris Warner And His Lady Friends". "Really?" laughs Galvin. "I want to frame it and put it on my wall!"

But first it needs updating. Recently, Chris has romanced former PA Libby, fellow surgeon Gabrielle, and dietitian Zoe. In coming weeks, watch for sparks between Chris and ex-girlfriend Rachel (Angela Bloomfield). "There's an enormous attraction that's either going to result in something good or something terrible," says Galvin

So, will Chris ever give up the womanising? To be fair, he's long been looking for (another) Mrs Warner to settle down with. "He doesn't see himself as a womaniser, but they just keep getting away," says Galvin. Blame the writers. "It's definitely more boring when the character settles down. I'm not sure I'd want that to happen either."

In the meantime, there's a pretender to the Dr Love throne: Chris' cousin, housemate and protege Dr Isaac Worthington (Matt Minto). Though Isaac's a slightly darker character, the hotshot surgeons are clearly blood relations: there's the same cockiness, privileged upbringing, ambition, drive to excel - and the womanising.

As Chris noted when Isaac dated three women in his first week: "He's playing the field and leaving the women in tears, much like me". And although Isaac's only had eyes only for fiery nurse Tania (Faye Smythe), he can't shrug off that player rep. As he said to Tania: "People have got me all wrong. Last night, was I out on the town with a beautiful woman? No. I was here until all hours doing my homework. Will the world believe me? No chance." Doth he protest too much? With Isaac and Tania facing some hurdles in upcoming episodes, don't assume he's a one-woman man just yet.

Amiable, softly spoken and happily single, Minto, 31, seems the polar opposite of ladies' man Isaac. "I wouldn't go sleeping round. I'm usually pretty shy and I don't have all the [pick-up] lines."

Chris, who even when breaking hearts technically treats women well, has been trying to teach his smooth-operator cousin some dating protocol. Advice is shared off-screen, too. "I was pretty nervous when I started," says Minto of his first major TV gig, "so it's been great working with someone of Michael's experience."

Deadpans Galvin: "The sum total of my advice was to stand up straight in the operating theatre." And maybe the odd tip on how to woo the ladies, Dr Love-style.

Shortland Street screens weeknights on TV2 at 7pm.
Shortland Street: From The Beginning airs on TVNZ 6 (Freeview channel 6 or Sky digital 016) daily at 8pm, repeated at 11.30pm.