Lived there for 20 years, married a local girl, now in my forties I decided it’s a young man’s town and I moved to Australia a couple of years ago.
There is a hard work hard play ethic, you will always feel like a ‘visitor’ rather than at home, friendships are fleeting as everyone is transient and only interested what they can use you for, and the expat life is a bit like la la land – its not real!
But… jobs pay well, life as an expat is privileged and comfortable, and if you can resist the temptation to act like 99% of people who go out there (party hard, become too full of yourself, and spend all your money on fleeting indulgences) there is a minority who manage to lead a very normal life, enjoy the active outdoor lifestyle available in Hong Kong (yes its there if you look hard enough), travel extensively around the rest of the region, and save enough money to retire very comfortably in a country of their choice.
My advice, decide what you want to get out of it (party for a few years vs. stash away as much money as possible for your retirement) and stick to that plan despite the distractions,and you’ll do all right…