Manners are important: this is actually a thing in Chinese culture. My grandfather in America for university, came back to China to visit his mother, and said thank you when she served him dinner. She then proceeded to yell at him for doing so. "What do you mean thank you! I am your mother!" In China, saying thank you is usually only for strangers, and the translation for the proper response to a 'thank you' in Chinese is "do not thank."