I remember seeing The Titanic many years ago when it came out. During the scene where Kate Winslet poses topless for Leonardo, the artist, I was sitting next to a couple with their 8-or-9-ish year old children. It took a couple delayed seconds for the husband to react and shield his kid's eyes. During that time, the kids didn't flinch; the parents eventually did. Perhaps the kids didn't see anything wrong with seeing boobies - but now they associate them with something forbidden.