I think one important cultural difference is related to jokes. I mean, each country has his own jokes which can be funny for the people who live there, but pretty stupid for others. This is not a very big problem but imagine you are with your chinese friend and you are trying to be funny and make him laugh, and then you tell him a very amusing joke for you, but so bad for him.
You'll look quite ridiculous!!
See? In some cases is better not to translate them because seriously, they're bad.
A very clear example could be english jokes:
- Teacher: How can we get some clean water?
Student: Bring the water from the river and wash it... - Q: What do elephants have that no other animal has?
A: Baby elephants. - Q: Can a kangaroo jump higher than the Empire State Building?
A: Yes, because the Empire State Building can't jump! - Q: What's the most musical bone? A: The trom-bone!
See? In some cases is better not to translate them because seriously, they're bad.
Hope you like them! :)