Large numbers of tourists fly in to visit the people of Hong Kong at Lunar New Year. Large numbers of Hong Kong people flee from the SAR at precisely that time. It is kind of like a population swap.
If you have friends coming from overseas, here is your guide to the histories of Hong Kong's favourite icons.
Abacus: The world's first computer was invented in China 3,000 years ago. It is still used in Hong Kong shops. Check out the counter of the Luk Yu Tea House in Central. Former legislator Peter Wong Hong-yuen told me he once met a Beijing accountant who did his maths on an electronic calculator - and then checked that the digital answers were correct with his abacus.
Bauhinia: Hong Kong's flower was first discovered by French monks in 1908, near some ruins on the seashore of Pokfulam. The symbolism inherent in the fact that it is a sterile hybrid has not been lost on commentators.
Colonial history: If you live in any of the following places, your address contains the name of a previous governor or administrator: Pottinger Street, Mount Davis Road, Bonham Road, Bowring Street, Robinson Road, MacDonnell Road, Kennedy Road, Hennessy Road, Marsh Road, Bowen Road, Cameron Road, Barker Road, Nathan Road, Lugard Road, May Road, Stubbs Road or Peel Street.
Domestic helpers: In the 1970s, Western families in Hong Kong started hiring maids from the Philippines because they spoke good English. Today there are about 180,000 Filipino helpers in Hong Kong.