I know that is a great point. If it wasn't for some of my earlier exposures to R rated movies and porn mags ( I got in trouble for looking). I'd probably be one of those adults who didn't seem to know anything in the world. True I still have a lot to learn and experience but at least I know it's out there.
I remember my 18-year old RA would freak out if she say a girl on MTV show cleavage, while I would grow up seeing blurred out nudity on the channel
Even though she was supposed to be very smart and well travelled she just seemed a little jaded or something.