Me-Man.....Fuck you teen
A teen is someone who is constantly getting discriminated against, like blacks used to.
Unfortunately, the majority of adults fail to see that. (See bias or ignorant.)
At eighteen and nineteen, even if there's the word TEEN in the number, you're an adult, not teen.
Look at the definiton of adult, 18+.
It wouldn't make sense to be both an adult and teen.
Also, "adult" movies are always 18+.
You'll often hear "A TWENTY year old TEEN got caught in an accident..." in the news, but they just want to sound clever. (it actually fails, because no one looks clever by calling a twenty year old adult "teen")
Tis culture was based around 'getting laid', being mean to nerds and of course music which appeals to teenagers. In the 60s another social change occurred in the USA whereby the war in Vietnam caused social unrest, this coupled with contraceptives and superior music to the previous decade caused teenage culture to become more deviant than ever.