A leading mainland writer has urged Hongkongers to stay vigilant to prevent the city's hard-earned culture from gradually fading away.
Bi Feiyu, one of China's best-known authors, said he had observed "subtle changes" in the city that might seem trivial to locals but were significant to him.
"Unlike my previous stay in 2009, people here no longer say 'excuse me' or 'I'm sorry' when there is bodily contact as they used to. I did a small test on the MTR with my shoulder at one point, but the contacted party did not respond," said Bi, who is spending a month in the city as writer-in-residence at Baptist University.
"I see that as an early sign that Hong Kong is becoming like the mainland. If these sort of things keep happening, it will affect the quality of the city and the people in it," said the 50-year-old novelist, whose Three Sisters won the Man Asian Literary Prize in 2010.
Bi is best known for his approach to sensitive social issues, such as the treatment of disabled people. Most recently, a film version of his acclaimed novel Blind Massage won an award at the Berlin Film Festival.
He says he sees the novel as a "philosphy, a life view", and that in creating and falling in love with the characters he creates, it "helps me [learn] how to confront life".
"Good habits take hundreds of years to develop, but losing them could happen very quickly. Hong Kong people should be proud of their culture and etiquette. Safeguard it and don't let it fade away," he said, acknowledging the effect that Hong Kong's colonial past had had in shaping the territory.
"Colonisation is bad, but the diverse culture that comes out of it is good."
One way to ensure a cultured society, he said, is to maintain high standards of cleanliness. "Hygiene is culture," he said.
Citing an inscription he was invited to write at a literary event in Shanghai a few years ago, Bi said: "Instead of writing 'love books' or 'love the motherland', I wrote, 'Wishing for sparkling clean toilets at Shanghai Book Fair'.
"I said that because of my experience at the Hong Kong Book Fair, where the toilets are so clean that if you drop a scoop of ice cream on the floor, you could still pick it up and eat it," he said.
"That's why I feel very unhappy whenever I hear mainlanders talk about Hong Kong being a cultural desert. A place without culture would not produce civilised citizens, teachers or students. It's as simple as that."
Such remarks tie neatly with the recent row over a mainland couple allowing their toddler to urinate in the street in Mong Kok. The row has sparked protests from Hongkongers over the behaviour of mainland tourists.
Bi called on Hongkongers to "be more tolerant towards the mainland people, who, for their part, should enhance their code of conduct".
"I must say a good number of mainlanders, especially those who visit for the first time, are impressed with Hong Kong's civility and orderliness, and often talk about it when they return. In that sense, I think it is a good thing for more mainlanders to visit Hong Kong," he said.
"But it is necessary to regulate the number of visitors. It was very crowded during my visit five years ago. I feel it's even more crowded now.
"When a given space, however attractive it is, becomes overcrowded, it will lose its charm. A family of four is nice. But when 40 people are crowded into the household, that will spoil the well-being of that family."
In contrast to the "subtle" changes in Hong Kong, he said China was altering at a far quicker pace and the future was difficult to envisage.
"China is going through rapid changes now, please note I'm not using the word development here. When I ride on a bicycle, I can see both sides very clearly as I pedal along. But now I feel like I'm riding on a bullet and it moves so fast that I can't see where I'm heading to."