I've always wondered if there isn't something sort of well-meaningly counterproductive in giving bullies and bigots a detailed guide of what not to say and why... kind of like preventing aircraft hijackings by giving a guided tour of which exactly which buttons in the cockpit not to press...finlay wrote: she didn't want to single anyone out, so she told everyone, but she had to explain what it meant first.
Anyway, I've no idea when I learnt the word 'gay'. The concept always seemed pretty obvious - I mean, I grew up listening to Tchaikovsky, reading Wilde and watching episodes of A Bit of Fry and Laurie, so it was hard not to have some concept of homosexuality. I think I probably was first aware of the word "gay" in the sense of "lame", but not all that much - at a young age, the word was "rough", or for particular emphasis "spastic"/"spaz" (with a brief excursion into "scope"), and in some contexts "gutting". There was a brief period of "lame" in secondary school, developing quickly into "crippled", before settling firmly into "pikey". After I left school, the government discovered heretofore unknown (in this part of the country, at least) etymological difficulties with "pikey", and started putting people in jail for using it, so I don't know what people used after that. They may have transitioned straight into "chav" (because of course that's totally different, nobody could object to that!).
Anyway, a small but noticeable number of people at my school were gay, so using "gay" as an term of depreciation would kind have been rude, so AIR everyone moved away from that fairly quickly.