The Butter and Cheese Question

The first day I went to Berlin, Germany, started my life in the Western countries. I watched a lot of Western movies before that point in my life, however, my feeling then was "things are rather different here than those in my mother country". 

Chinese do not have many dairy products on the market except milk and yogurt. Butter and cheese are things that are typical foreign products (yang2 huo4) in people's eyes. Naturally, ordinary people never tasted them in their lives, including me when I was in China. However, every one knows they are made of milk. 

With this knowledge in my mind, I went to Germany, the first Western country ever. I happened to be invited by the boss for a dinner just a few days after I arrived. At dinner table, I sincerely put forward a question: "What is the difference between butter and cheese?" People at the table answered me sincerely and thoroughly. Suddenly, I was so clear of their difference for the first time in my life. I gained knowledge! This was my only thinking at that moment.

Months passed after that dinner. I got acquainted with other Ph D students in the same department. Some thought I was cute! One day, a Canadian girl S could not help iterating my question of butter and cheese. By then, I finally realized how silly and cute I was when I was asking that question. On the other hand, I believe that people at the same dinner table rather amused quietly! 

This question was mentioned quite a few times afterwards by other guys. Thinking back, I guess people at the dinner table were rather polite and understanding. I cannot know if the same reaction will be given elsewhere else. 

BTW, dear readers, do you know the difference between butter and cheese?