Water pressure is high (could be building/location specific)
Some keypads (ATM, phones...) start with 1 in the upper left, some with 1 in the lower left. This really kills muscle memory.
Pedestrian crossing beep once per second when you aren't supposed to cross, and do a rolling beep when you can (in addition to the walk/don't walk signage). Newer escalators also do this - a slow beep meaning that you are going the wrong way.
Cars don't stop for pedestrians.
Pedestrians don't stop for pedestrians. Walking in Hong Kong is frustrating, you'll get cut off and people will seem like they are coming right for you. There's obviously a trick to it, because I've paid attention and no one else is running into each other. I'm doing something wrong...like looking up.
If you're buying something that says 3 for $10 - don't buy 4.
In Canada, with its suburbs, convenient stores charge a premium for being conveniently located. In Hong Kong, every store is convenient, so the many 7 elevens don't see to have that same premium.
If you plan on standing on an escalator, stay to the right. The left is the passing lane.
Air conditioners blast full strength and stores have no doors. Even huge buildings, like HSBC's headquarter, have air conditioned space opened to the elements.
Adidas's whole body antiperspirant spray ads don't seem so silly on day 2.
Buildings are so high, the region so mountainous and streets so curvy that trying to use the tall ICC and IFC2 buildings as points of reference is futile.
Although Hong Kong is made up of three parts - New Territories to the north, Hong Kong Island to the south, and Kowloon in the middle, Hong Kong refers to the island.
Although Kowloon is physically attached to China, it is not considered the mainland. So, when you land at the airport and you want to get to Kowloon, don't follow the mainland signs like I did.
Shopping malls don't have food courts. Restaurants are spread out all over the place.
Shopping malls, including the fanciest ones, have very few, if any, places to sit (except for restaurants).
Shopping malls have a lot of staff standing in the mall. They are definitely able and willing to provide information, but they might also serve a security purpose (not sure).
There is no residential recycling.
The MTR (subway) trains get really cold when moving.
Hong Kong island is very safe.
With low income tax, no sales, capital gains, or corporate taxes, the Hong Kong government makes its money by leasing land.
Metal and rubber studs/markers can be found throughout malls. This is to assist the blind.