That he is a friend from high school tells you about his relationship with me. It answers the question, "Why do you, carbocation, care what this person thinks?"
Note that I didn't tell you about his skin color, the color of his hair, or anything else that wasn't actually relevant. Prejudice is a tough nut to crack and is not the same thing as bigotry.
In that case, you could just tell me he was your friend, not high-school friend. Or better yet - "Person I care about ...". If being too specific was bad.
Anyway - I don't see what this has to do with prejudice or bigotry. People add details to stories, because that makes stories better (at least in the opinion of the people that tell these stories).
I live in Poland, there are very few people other than white here (like, I've met black people maybe 10 times in my life), and when someone tells a story, nobody mentions race (because it's assumed to be white), but people tell "So this big bald guy says ...", or "And that gray old lady did ...". That's just how people tell stories. Is this prejudice, too?
And if I met black person and something interesting happened, I'd tell in my story, that this person was black, because I'd certainly remember that as a distinguishing characteristic, exactly like being big bald guy, or being grey old lady. Or I could skip "gray", because "gray" is the default visualization for old ladies.
Note that I didn't tell you about his skin color, the color of his hair, or anything else that wasn't actually relevant. Prejudice is a tough nut to crack and is not the same thing as bigotry.