When I was growing up in the 1960s, I was taught by the adult world that good girls never had sex and bad girls did. This rule had clarity going for it but little else; as it was presented to me, it allowed no room for what I actually might feel. Within the confines of this rule, I didn’t count for much, and I quite vigorously rejected it. Then came the less clear “rules” of cultural trend and peer example that said that if you were cool you wanted to have sex as much as possible with as many…