I think it is because of ignorance, it's like taking an addictive drug without following up on what it does to you. I was actually one of the kids who paid attention in sex ed class, I take interest in it because I know that it is valuable information, & I talk to my boyfriend about "sexual" topics, mostly just bodily functions, why they react the way they do, & he will just sit their with this wild face while I go on, he'll stop me & say where did you learn all of this from ? I mean its not like I was the only kid in the class, it was required ! How is it that no one paid attention ? & the answer is ignorance, immaturity: I was in that class in 8th grade, kids havent had the experience & most giggle or think they know EVERYTHING about sex. Teenagers have the same response though, they have sex because they enjoy it, they only respond to pleasure, thats all they understand, but when it comes to learning about it, what it there to learn? you just do it because it feels good, & as absurd as this sounds, this is what people think, sad really.