But never mind. "You really must come and meet my family. All of them," says Jo, pushing these irreconcilable realities firmly to one side. "They would love it, I'm sure. If you like, one day next week you can come to my house and have coffee."

I would like that very much, I say. But it's not going to happen, of course. Jo Verhoeff is 86. Her husband died a decade ago and her parents passed away many years earlier. The kids are getting on a bit themselves now. Jo is confused. Doctors have diagnosed her as suffering from severe dementia, and she lives at Hogewey. But like most of the residents at this Dutch care home, she seems serene. In fact, she seems happy.

Dementia is now acknowledged to be one of the most pressing problems facing health and social care systems. A report published by the World Health Organisation this year predicted that a continually ageing population in the developed world would mean the number of people with the condition was likely to double, to more than 65 million, by 2030, and treble 20 years later.

Rapidly ageing Hong Kong is among the communities at the sharp end of this trend. With 9.3 per cent of people aged 70 or above diagnosed as suffering from dementia, the Census and Statistics Department has projected that there will be 77,000 such people in Hong Kong by 2019.

Over the past few months, experts from around the world have been flocking to the small Dutch town of Weesp, 30 minutes from Amsterdam, to see how one pioneering institution is dealing with that challenge.

"What happened is that, in 1992, when this was still a traditional nursing home for people with dementia, two of the staff here unexpectedly lost their mothers," says Isabel van Zuthem, Hogewey's information officer.

"Each said to the other, 'Well, at least it happened quickly, and they didn't end up here. This place is so horrible.' Then they realised what they'd said, and thought, 'What kind of home would we like for a relative with dementia? Where might we want to live, maybe, one day? How would we like our life to be?'"

The answer turns out to be this complex, completed in early 2010. A compact, self-contained model village on a 1.6-hectare site on the outskirts of town, half of it is open space - cosy side-streets, sheltered courtyards and well-tended gardens with ponds. The rest is neat, two-storey, brick-built houses, along with a cafe, restaurant, theatre, minimarket and hairdressing salon.

Hogewey's 152 residents, who are never called "patients", have all been classified by the Dutch health service as suffering from severe or extreme dementia. Averaging 83 years of age, they are cared for by about 250 full- and part-time staff. They live in 23 homes, six or seven to a house.

Two core principles governed Hogewey's award-winning design and inform the care that's given here, says Van Zuthem. First, it aims to relieve the anxiety, confusion and anger that people with dementia can feel by providing an environment that is familiar.

It's an almost-normal home where people are surrounded by things they recognise.

Second, it's about "maximising the quality of people's lives. Keeping everyone active. Focusing on everything they can still do, rather than everything they can't. Because when you have dementia, you're ill, but there may really not be much else wrong with you."

So Hogewey has 25 clubs, including literature, bingo and cycling. It encourages residents to keep up the day-to-day tasks they have always performed such as gardening and shopping, going to the hairdresser, popping to the café. "Those small, everyday acts are just vital," says Van Zuthem. "They stimulate. They give people the feeling they still have a life."

The homes belong to seven different "lifestyle categories" where moods are evoked through choice of furnishings, decoration, music, even food. One is , or Dutch upper class: ornate chandeliers, lace tablecloths, fine dark reproduction furniture, and a kitchen discreetly concealed behind a screen. Here, says Van Zuthem, "the carers behave like servants. Many of those who are here will have had a maid".

Across the courtyard is a house in style, for people who were once in trades and crafts: farmers, plumbers, and carpenters. The furniture is heavier, the curtains darker, the decor simpler. is for homemakers: neat, spotlessly clean, display cabinets for dozens of brass and porcelain ornaments.

Toos Borst, also in her 80s, isn't sure she lives here: "Do I? I don't know really. It's very nice, though I'd really prefer to be home, in Wateringen. You know it? Near the Hague. My mother's there. My father has gone, sadly. Here are pictures: my great-grandchildren."

Washing hangs on a line. Apart from the main entrance with its hotel-like reception area, no doors are locked in Hogewey. Residents are free to wander where they choose, and visit whom they please. There's always someone to lead them home if needed.

Others are gathered round an old-fashioned sweet stall, swaying to Dutch oompah music from the 1950s.

"They did it themselves," says Marjolijn de Visser, a cheery young careworker, pointing to the brightly-painted shutters on the stall. "It's really important that residents feel like they are contributing."

Other houses are designated , for the more religious residents; , for those who enjoy art, music and theatre, and , for residents from the former colony of Indonesia. The latter have rattan furniture, Indonesian stick puppets on the walls, and authentic cuisine.

Last comes urban, for residents who once led a livelier lifestyle: contemporary Scandinavian-style furniture, on the stereo. Here, Theo Visser, who used to run his own road haulage business, is playing cards with his wife Corrie, 79. He travels 13 kilometres to visit her every day.

"We've been married 57 years," says Theo. "She looked after me all that time. It's the least I can do."

Hogewey is unique, Visser says. "The people here keep their independence, as much as they can, and they stay active. They still have a life. It's not the sort of slow death you get in other places."

Hogewey cost €19.3 million (HK$188 million) to complete. The Dutch state funded €17.8 million and the rest came from sponsors and local fund raising. The cost per resident is not much higher than most regular care homes in, say, Britain: €5,000 a month is paid directly to Hogewey by the Dutch public health insurance scheme. Some pay a means-tested sum to their insurer. The waiting list is long.

In its early days, Hogewey was dubbed a , after the Jim Carrey film in which reality turned out to be the set of a reality TV show. Eloy van Hal, who works as facility manager, says the home is "not completely normal. We pretend it is, but ultimately it is a nursing home, and these are people with dementia. Sometimes the illusion falls down. They'll try to pay at the hairdresser's and realise they have no money."

"We can still do more," adds Van Hal. "But in general, I think we get pretty close to normal. You don't see people lying in their beds here. They're up and about. They're doing things. They're fitter. And they take less medication."

Across the piazza, in the wood-panelled cafe, careworker Helene Westerink is leading 30 residents in the weekly classical music club.

"There's one woman here who hasn't spoken for years," says Westerink. "But she sings along to all these tunes. You know, sometimes it's not just the residents who feel good about being here."