I'm a retired Scottish secondary school teacher. I normally avoided the topic as well.
However...One time a teenage boy was mouthing off about his participation in Orange Walks and how he hated Catholics.
"Why do you hate Catholics?"
"Cos I'm a Protestant."
"Are you a member of a church?"
"Naw. Only Catholics go to church."
"I beg to differ. I'm a member of the Church of Scotland, so I'm a Protestant."
"Protestants don't go to church."
"I assure you that they do. You're telling me that you've never been inside a church..."
"It's just Catholics that do that."
"So what makes you think that you're a Protestant?"
I can't remember the full conversation now, but the poor lad seemed to think that "Protestant" meant "atheist". I suppose that he might have tried to make a case for "Protestant" as signifier of cultural rather than religious belief but he wasn't up to that: I rather think that he also believed that only Protestants played the flute [badly].
I half expected a parental complaint, but there was none.