One way to tell that something’s normal is that we’re happy to talk about it freely and easily in front of children. That’s what Britain’s LGBT children were deprived of for 15 years (slightly less in Scotland) by Section 28, a late Margaret Thatcher-era homophobic law banning the “promotion” of homosexuality, or any teaching that included “the acceptability of homosexuality as a pretended family relationship”.
In practice, this meant that schools across the country decided they simply could not mention same-sex relationships -- depriving older students of useful sex education, but much more broadly making any kind of LGBT role models completely invisible for a full generation of students. I would know: I was one of those students. Section 28 covered all but my very final year in the UK school system. Of the (at least) five of us in my year who later came out as LGBT, only one did so in school -- and surely came to regret it, given the bullying that followed.
When the law changed, the school changed fast: when relatives went to the same school less than five years after I finished, being gay was a non-event, even in the lower years.