34 years ago I began engaging in sexual behaviours. No internet porn then, nor had I seen any explicit sexuality in movies and didn't need any encouragement to know what I wanted to do. Nor did anyone prior to media being invented. It's natural biological functionining to begin desiring sexual pleasures around the onset of puberty. And even long before those sex hormones start producing themselves very young children desire sexual gratification by way of masturbation. Though here I don't know if it's accurate to call it sexual pleasure so much as they just know those parts feel good, but would assume they're not imagining naked people like their pubescent brethren would be.
As a media watchdog of sorts I've seen how what's permitted on commercial tv has evolved during at least my own lifetime. Other than profanity and violence though, sexuality is still forbidden. Can show the human body being blown apart, but not a woman's nipple (though oddly a man's is ok, and so is a fat man's 'boob') And you can't show an erect penis anywhere but on PPV. So I wouldn't agree US media is especialy sexualized. Overly tolerant of violence absolutely.
We're basicly upset about the wrong things though. We tolerate violence, but not sexuality. That's reversed to how it should be. One's objectively bad, the other isn't and it isn't sex that's bad. Everyone wants sex eventually (for all intents and purposes) but no one wants a homocidal whackjob runnin gthem down with a chainsaw.