Every so often, a television advert comes along and appears to capture the public’s imagination – remember Meteor’s man from the bar, or Guinness’ loose-limbed dancer? And now an unassuming real-life couple from Co Kerry – she a home-maker, he a taxi driver – find themselves embedded in Irish culture.

In AIB’s latest campaign, the affable Kate and Mick O’Sullivan reflect on their journey from down payment to the very last day of their mortgage. Their reflections are intercut with old photos and home movie footage of their children Connor (23), Genevieve (25) and Devlin (14).

From renovations on their home to raising three orthodontically challenged children, it has, by the couple’s admission, been a financial challenge. But they got on with it. And now, finally, they can ostensibly enjoy the spoils.

So far, so unremarkable; couples pay off their mortgage all the time. This is a fiscal journey known to almost every family in the state. And yet there’s something about this ad campaign that has genuinely lit the blue touch paper.

For audiences of a certain age, Mick and Kate are the Irish ideal writ large. Hard-working, conscientious, wholesome, solid. For a younger audience, they – and clever ad campaign – hammer home one simple but brilliant truth: the millstone of the mortgage isn’t one to be carried around forever.

Though it rarely feels like it for a new homeowner, the day will come that the mortgage will be no more. You too can look as glowingly content as the O’Sullivans, once you put the 30 years of monthly repayments in first.

Social media is pushing the couple's notoriety, too: "Do you think they take in waifs and strays?" one friend posted on Facebook recently. "I wonder would they adopt a fully grown woman?" mused another.

Mick and Kate are slightly perturbed at the wave of attention. When they hear of the potential adoptees in Dublin, they laugh disbelievingly.

“Initially we just heard from family and friends about the ad,” says Kate. “Next thing, we had complete strangers coming up to us, telling that they cried and got very emotional, which is interesting. I was like, ‘if you didn’t know us, how could you be emotional about us?’”

What were they emotional about? “Maybe in this current climate where their kids have gone through university and left, and they’ve seen us welcoming ours back into the house, they can relate to us.”

Nearing the end of their mortgage last year, the couple were contacted via an ad agency; the bank had pinpointed a number of others in a similar financial position, but agency bosses clearly warmed to the O'Sullivans. The production company trooped to the family home outside Killarney, and started filming a week or two after they actually finished paying their mortgage.

“Oh, the director couldn’t have been kinder,” says Kate. “He didn’t want us to be scripted and he made the whole thing just feel so natural. Filming it was a poignant moment, as it made it all [the end of the mortgage term] feel real.”

Which begs the question: how did it feel to get to the end?

“To be honest, it’s not something we were all that anxious about on a day-to-day basis,” reflects Kate. “Call it naivety but it’s just about believing you’ll get through it. We weren’t sitting in with a watch and calendar or anything. It’s more like, ‘oh, it’s here. It’s done now. Let’s move on to the next challenge’.”

When they bought back in 1994, Ireland’s financial terrain was very different. Yet, by the time Mick and Kate found the presbytery they wanted to turn into their dream family home, they had undergone plenty of hard yards by then.

The two met on a street in Cork one Sunday morning in 1982, ahead of the Siamsa Cois Lee music festival. Kate, originally from Long Island, New York, was spending the summer working in Ireland with two girlfriends, and the three randomly happened across three young men.

“There wasn’t a sinner on the street,” recalls Kate. “So if you believe in fate, it was quite something that he happened to be there. I thought he was quite good-looking.”

“I remember saying to her ‘would you like to go to Mass?’” smiles Mick. “There was definitely something special about her. My best friend took me to the side though and said, ‘you watch her, she can be trouble yet’.”

That year Kate had decided to stay on in Ireland, but the death of her mother brought her back to the US. The pair stayed in touch via letter and conducted a long-distance relationship for six years, before Mick moved to the US in 1988.

By 1994, Mick’s own mother was experiencing health woes, and the family – Mick, Kate and pre-schoolers Connor and Genevieve – moved back to Ireland.

Getting a mortgage in 1994 was the easy part; finding their dream home was anything but.

“We’d seen [the presbytery] a year before we bought and it because [the sale] was going through the diocese, they had to get authorisation,” explains Kate. “Nothing else was a really good fit. I left that summer and said ‘if it comes up for sale and we don’t get it, maybe we should move back to the US’.

“Fortunately for us, a lot of other people really could see behind the priest decor. It hadn’t had a family in it since 1904. It needed a family.”

It also needed an unholy amount of renovation, too: “There was a tremendous amount of work involved, and it’s still ongoing,” says Mick. “Owning a house like this is a forever game, but on the upside, you don’t have to make a phonecall to the landlord to do this and that.”

With a little help from Kate’s carpenter brother Dennis and family friend Murt O’Shea (“only for him it’d still be going”), the family rewired, replumbed, installed floors, lifted walls, insulated the house and dry lined the walls.

“The house had never gone through a focused renovation so we said we’d gut the whole thing and start afresh.”

The couple had already cut their teeth on a previous renovation, but Mick still recalls one minor error: “I made the mistake after getting the walls primed, that it was okay for them to make chalk paintings on the walls. We hadn’t picked our colours yet so we have to re-prime the lot.”

Adds Kate: “It was no easy work, trying to find time to rear the kids, work, schooling, trying to juggle everything and make sure everyone was happy. But if you’re a parent and house owner, that’s what you have to do.”

Having lived for a spell in Dubai, Connor and Genevieve now live in the US, while Devlin remains at home: "Almost done," smiles Kate. "Although of course, you're never done worrying. And the kids do look forward to coming home as much as we love having them home."

“We try not to worry about them too much as it doesn’t serve a purpose,” adds. Mick. “We’re concerned that they’re healthy and content and whatever decisions they decide to make, they are theirs.”

As to what advice they might have for those still on the financial treadmill: “Keep at it,” Mick says. “If you get knocked down, just get back up. And if you need a break, take one and don’t sacrifice your health. But don’t ever quit.”