In eight days, the Hong Kong Special Administrative Region will mark the 15th anniversary of its establishment.
Government officials, experts and the media are reviewing the successes and failures of the past 15 years from all perspectives, including the relationship between Hong Kong and the mainland.
But when people talk about the 'Hong Kong-mainland relationship' they are mainly talking about three different things: the boss-subordinate relationship with Beijing, the rivalry with Shanghai and the complicated relationship with the Pearl River Delta.
Besides selling drinking water and food to Hong Kong, Guangdong has also provided many other resources, such as land and labour. These resources went to Hong Kong entrepreneurs - who grabbed their first pot of gold by following the 'front shop, back factory' model in Shenzhen, Dongguan , Guangzhou and other regional cities - after the opening up of the mainland in the late 1970s.
But Guangdong has also been a source of trouble for its neighbour and that is likely to continue. It is the source of many of the non-resident mainland mothers who give birth in the city, and it will probably be the main source of mainland cars when they are allowed to enter Hong Kong in the near future.
It is good for a small place like Hong Kong to have a hinterland area like the delta and it should definitely make the best use of the region's resources.
However, the short history of cross-border co-operation since the handover shows that it has not been an easy task for either side from the very beginning.
A good example of this, and one that certainly matters to the future of millions of Hongkongers, is the fate of the Hong Kong government's 'Guangdong scheme' and its predecessor.
Hong Kong officials have been continually warning of the challenge posed by an 'ageing society' in recent years and are eager for solutions. Chief executive-elect Leung Chun-ying told the South China Morning Post three weeks ago that one of his top priorities after taking office on July 1 will be care of the elderly.
Official estimates two years ago said that by 2031, a quarter of Hong Kong's population will be older than 65. To handle one of the biggest long-term challenges facing the city, the Hong Kong government needs to provide more funding for elderly care projects and also find more space for the elderly.
It did try to think outside the box a decade ago. In 2001, when outgoing chief executive Donald Tsang Yam-kuen was still financial secretary, the first home for the elderly, for the exclusive use of Hong Kong people, to be set up outside the city opened in Zhaoqing , Guangdong.
Nursing homes in the delta can offer more space for less cost than those in Hong Kong, with some media reports saying that it costs less than 4,000 yuan (HK$4,900) per month to care for an elderly person in a delta nursing home, compared to at least HK$7,000 in Hong Kong.
Unfortunately, the pilot scheme did not expand for more than a decade, with many elderly Hongkongers reluctant to move to the delta, mainly because they were not allowed to collect their old age allowance there.
It was not until late last year that the Hong Kong government took the second major step, announcing the 'Guangdong scheme' as a part of the welfare policies in Tsang's last policy address.
Tsang said that starting from next year, elderly Hongkongers could collect the old age allowance in Guangdong if they spend at least 60 days a year in that city. He also promised to improve medical services for elderly Hongkongers living in Guangdong and to make it more convenient for them to return to Hong Kong for treatment.
Hong Kong government statistics show that there were about 900,000 Hongkongers aged 65 or above in October, with 76,000 living on the mainland - 65 per cent of them in Guangdong.
One question that has not been answered is why did it take so long for Hong Kong to work out the second step?
The inefficiencies built into Guangdong's administrative model, something Hong Kong institutions and businesses are all too familiar with, must take some of the blame.
To give just one example, The Hong Kong Jockey Club Helping Hand Zhaoqing Home for the Elderly told the media several years ago that it had only received its operating licence six years after applying for it.
Even though Supplement IV of the Closer Economic Partnership Arrangement, issued in 2007, says that Hong Kong institutions are allowed to set up nursing homes in Guangdong without having to enter into partnerships with local bodies, many Hong Kong businesspeople have complained that the obstacles put in place by Guangdong authorities in charge of the approval process remain unchanged.
Experts predict that regional integration will speed up as the basic infrastructure of the delta steadily improves.
With an increasing number of people likely to choose to live north of the border, it is time for both governments to work out a new model of co-operation that goes beyond the old 'front shop, back factory' one.