I have some friends from Vietnam. I met all of my Vietnamese friends in English classes in America. I became close friends with them really fast because we are all Asian. Our cultures are similar, so we can understand each other easily.
However, I was shocked by a difference between Vietnamese and Korean culture. My birthday is very close to my friend's birthday. We exchanged presents. I expected her to say "Thank you so much, I really like the present you got for me!" I waited for her for literally two days, and she never said anything. I thought maybe she didn't like the present that I gave her or she was mad at me or something else. I thought that because showing how much I am thankful for something that is given to me by someone else is a normal thing that is really important in Korea.
I texted her first and asked her if she liked the present I gave her, and then she said, "Thank you. I like the present!" I was wondering why she didn't tell me thank you before I asked her. I asked another one of my Vietnamese friends why she thinks that my friend didn't say thank you to me. My friend told me that that is Vietnamese culture. She said that in Vietnamese culture it is really awkward to say thank you. That explained everything.
Also, I asked one of my husband's friends, who currently lives in Vietnam, about this too. He said he asked his girlfriend, who is Vietnamese, if her parents buy dinner for him, should he say "thank you" or not. His girlfriend's answer was "You don't have to say thank you; you can say it was delicious instead." What she said agreed with what my friend had told me about their culture.
I thought Vietnam and Korea had really similar cultures, but how we express gratitude is very different. It was really hard for me to understand why Vietnamese people don't say "thank you." There are many people from other countries with different cultures. I have to try to understand that other people can think Korean culture is hard to understand too. I think it is always good to try to see things from others' perspectives.