In Japan and South Korea (the good one FYI) giving a tip is considered an insult, people do their job as best they can and need no additional money to be good at it.
Need to catch a taxi in Australia, New Zealand, Scotland or Holland? Things are different there and you are supposed to sit by the driver, or they will feel you are showing them they are worse than you. You can see that also in some parts of Ireland.
In the Middle East, South America, west Africa, Russia and Greece "thumbs up" is offensive and means the same thing as "the middle finger."
Showing teeth while laughing is offensive in Japan.
People in South America hate when people say U.S.A = America, because they are also American.
In Germany being late, even a few minutes, is considered a serious insult.
... while in Argentina it's good to be late a bit.
If you have your hand in your pocket in Turkey you are seen as arrogant.
In most Asian countries you should wait until you open your present until the person that gave it is not looking.
In Japan you shouldn't wear flip flops or tracksuits outside, EVEN when you're just going to buy some beer.
In France, Italy, Spain and Japan it's rude to ask for spices if you aren't given them, cause it's an insult for the person who made the food.
Showing the soles of your feet is very insulting to Muslims, Hinduists and Buddhists, they are considered filthy.
You may heard that you should leave your shoes outside in many Asian countries, but do you know it is also common in the Caribbean?
While in many countries taking someone else's beer is just a little rude, Norwegians consider this extremely rude.
Women yell "equality" when it comes to men being able to walk around topless, so Korea solved the problem prohibiting BOTH genders to be topless in public (that means also the beach).
In Rwanda and Japan you eat the meal where you bought it, walking on the street with food in your hand is considered rude in those countries.
In Asia if you're a guest in someone's house you can't get anything from the fridge yourself, you want beer- you ask for it.
In Holland you don't ask about occupation, other people's job is not your concern.
It's rude to decline if someone gives you food in the Middle East.
In China, Saudi Arabia, France, Turkey and Japan blowing your nose in public is considered highly gross.
In Japan and China you are required to decline a couple of times when receiving a gift and accept in the end.
You can't eat all of your food if you are a dinner guest in China, Philippines, Thailand and Russia cause that means your host did not provide enough food and he is shamed.