A childhood belief about wars

I once got in a lot of trouble in school, when I was in Grade 5. I was obsessed with battleships, and tanks, and aircraft and all that, which isn't really all that unusual. I was obsessed with World War II at the time, but no one had ever told me about the Nazis and the Jews. One time at lunch hour I was running around with some friends of mine, and I decided to pretend that we were planes from the war. We all got to be British planes, and when I ran into some other people I knew, they became the Nazis, which at that point I think I believed was synonymous with 'German'. Because one of these 'Nazis' was Jewish, my teacher yanked me into the classroom and gave me a stern lecture about how what I did was wrong, and then made me go out and apologize to this child, who (I think) was about as oblivious as I was. The teacher then called my parents at home, and I hid in the closet, because I was afraid they would be mad at me.

I'm not sure exactly why the teacher made such a big deal out of it, when a basic clarification of terminology would have fixed the situation... I'm still obsessed with the Second World War, but I know the difference between Germans and Nazis now. :)