Culture shock!!

I never really understood the word"Culture shock" before. But now that I have moved to Middle East, have got to know the exact meaning of the word. Now to give a glimpse into why I am saying its a culture shock.. Freedom of expression, I tend to think thats one word which people here dont know the meaning of. I have totally forgotten to smile at other human beings.This is because when a female smiles at anybody she is thought to be morally backward here.. So I follow,"Be a Roman in Rome".. Hence the above sentence..