When did 15 year olds become so cool?

Taylor Momsen, aka Jenny Humphrey from Gossip Girl arrived at the private Topshop dinner in New York last night looking very cute and quirky in a colour pop pink skirt and cropped biker jacket, and are those Emma Cook for Topshop boots I spy? When did 15 year olds become so cool? How did Taylor become so fashion aware by the age of 15? It's a marvel! She is even wearing coordinating pink lipstick! I can't even remember what I was wearing when I was 15 but it certainly wasn't this well put together and thought out! Sigh...