At what age did you first encounter racism or it wasn’t until later you found out?

When you first encountered racism in your life did you really know? Was it simply prejudice disguised as racism? When I was in the 4th grade about (and I am dating myself here, it was the late 60s) my best school pal was this red-head freckled kid (no Irish jokes) named Randy. During free play time we enjoyed challenging each other to building contest with the Legos. Then this blonde German kid cam to class and moved in on the 3some to make it a 2some with me out of it. No matter how much I tried to be friendly to him he was cold and distant. He didn’t want me to speak to Randy or touch anything he was playing with. It was still about 2 generations past WWII but I didn’t know about Nazi ideology. I just to call him a Nazi even though I didn’t know what they were all about because it enraged him. Later as I started to learn more about Hitler and his vision of the Master Race from history classes later on it kind of shed light on why this kid acted the way he did. If his father was in the war fighting for Germany his dad would have been between 45 to maybe 56yr depending on how young he was during the war and his grandparents would have been in their 60s to 70s and could have been supporters of that thinking. I chalked that up to my first “in your face” bout of racism, but at the time I know I didn’t like it I just didn’t have a name for it. Did you have such a memory directed at you, your family or your parents?