Yes hollywood goes door to door telling every woman what to think and slips subliminal messages in the television feed of those that won't answer the door.
No you fucking ape.
As social creatures, we pick up a lot of our habits based on observing others in a passive fashion. You do it even if you don't know you're doing it. It's not iron clad, but it's a big factor in to how you behave regardless. Particularly when it's a subject that is not talked about openly, you form assumptions via example. Women in traditional media bring up the idea of shaving as if not doing so is morally abhorrent. Parents in America are incredibly adverse about talking to their kids about anything related to puberty. Adults don't want to acknowledge that kids are in the midst of becoming sexual. Hell, even losing your virginity before you get The Talk wouldn't be odd. With no one feeding the majority of women any other idea on what to do Down There, media is ALL TOO HAPPY to fill that gap with it's own ideas. Who do you listen to when no other voice is speaking up?
It's the natural result of willful information gap. Media didn't even have to *try* to control it.