I understand brain development but the rate at which one's brain physically develops is not the only factor in maturity - I am well aware that anecdotal evidence is not data but, in my experience, age is a poor indicator (posted to Silly Teenagers, Sex is for Adults!)
That comment bugged me too, for the reasons you mentioned... I only mirrored it back in my writing for the sake of argument... personally, I would never use that phrase on my own especially since it shows disrespect to the (posted to Silly Teenagers, Sex is for Adults!)
I was really thrown by that comment, both because of what you mentioned and because it seems to be assuming everyone is going to get married at twenty. (posted to Silly Teenagers, Sex is for Adults!)
Explosion ahead: This is insane. Teenagers do make their own decisions about sex, and it has a lot to do with new and exciting physical urges. Yes, we live in a complex culture, but we're still animals. Maybe it's because (posted to Silly Teenagers, Sex is for Adults!)
I'm abstinent by choice and don't have much "sexual experience" and I guess you are entitled to your opinion, but seriously, not everyone shares it. I'm sure there are others who date and even -- gasp -- marry someone with (posted to Silly Teenagers, Sex is for Adults!)