We don't refuse to learn about other countries it's just they don't teach us. I mean we do learn about ancient civilizations at a young age then we go into the physical features for our country and finally all the political aspects and then for the final one or two years of high school we get to explore options to either go more in depth with our history or learn a different countries history. Also with the internet being available to most Americans nowadays we can access the entire history of any country we want. I personally researched a bit about Japan just because I thought it was an interesting country.