I remember in high school (I'm in the US), we learned a lot about ancient greece, a little bit on ancient Egypt, and a whole TON of the history of Europe. The chapters focusing on Asia, middle east, and the rest of africa are sparse and few. Why is this? Was there not as much going on? Not as fascinating? Am I just imagining this?
School systems typically develop a curriculum relevant to their own history and culture. Since you're from the US you are from the west and your history and culture is very much tied to that of Europe. I'm in England, I learned nothing in school about US history for example. Not a single thing.
I suspect if you grow up in Asia or Africa your history lessons will be much more locally focussed, you'll not be learning much about European and US history.
Because you're from the west? You can only teach so much in so many years, so they teach about things relevant to you.