“Can men and women be friends?”
What made the film “When Harry Met Sally” memorable for me — aside from the “orgasm” of Sally (Meg Ryan) at the diner — was this intriguing question, provoked by Harry’s premise/presupposition that men and women cannot be simply friends because sex almost always enters the equation.
(In another movie, I think “All of Me,” Steve Martin gets confronted by his wife — “I faked all my orgasms!” — who proceeded to demonstrate this by having “one” right in front of him in his very office. Steve Martin, humiliated, replies, “Well, so did I!”)
Of course, as Harry (Billy Crystal) grows and matures in the course of the years, he revises and modifies his theory but basically retains the core of his presupposition.