Same here -- I think at the point I found those I already had a decent idea of the general mechanics from a mix of nature books/documentaries, medical reference books (my mom was a nurse), and the creepily outdated 1950s facts-o-life pamphlets my mom had been hanging on to for when she had kids, and I'm pretty sure I'd come across other sex scenes in fiction at that point, but nothing quite as detailed as Auel. But that was also the same year the Brooke Shields remake of The Blue Lagoon came out -- one of my calabash aunties took me to see that, along with her slightly older kids, because it was ~educational~; and that was simultaneously thrilling because it was the first R film my mom had allowed me to watch, and somewhat embarassing to be watching all that sex stuff with grownups. So yeah, between Ayla and the Lagoon kids, 1980 was a good year for disturbing sexual-awakening mass media. o_O