Jilla wanted a mother-daughter thread, so here it is, complete with hasty intro.
Generational divide is one tool of the patriarchy, ageism. It is particularly prevailent in societies of the nuclear family structure, which frequently involves a lot of separation of the females from her family, leaving her to do childraising on her own.
Some of the other mechanisms that also interfere with one generation passing on info to the next, particularly the female lines, include religion. In my grandmother’s generation, “sex” (meaning PIV) was “something you did not talk about”. It was not because that generation did not “know” about PIV (after all, my grandmother gave birth to eight children, so she got the drift), but all the pitfalls, the duty, the drudgery of PIV were also not able to be passed down from mother to daughter, because it was labelled a taboo subject.
Anyway, just another divide-and-conquer tactic in the arsenal of the patriarchy.