I would imagine most kids do as well.

When I was younger porn was not nearly as accessible as it is now. Most the online stuff was pay walled, so there was soft core stuff on those late night channels. I would be up late and watching tv and it would go from a regular movie to raunchy, scandalous commercials.  

The internet also didn’t have as much easy to find information as it does today. Wikipedia has the basic information and links to resources/publications that are relevant to whatever topics. Twitter and Instagram put it all in your face.  

Unless you are one of those parents who has all content child locked and monitored (I think this parenting style is so WEIRD, btw), at 10-15 your kids already know what’s up or have at least some idea. They’re at or about to hit puberty and becoming attracted to people.  

So if you’re discussing porn with them, on the younger side of the spectrum, maybe explain in light terms.  
But at 15... May as well give em the spiel.

And not paying attention to the news. Days of innocence.