Ooh, ooh, I actually have something to say!
Maturity is an illusion. It is an arbitrary standard that means nothing except how much other people trust you, which, if they get to know you, they should trust you anyway. So, maturity is simply a way for people to generalize you. Which we all know doesn't work and is bad. So, you aren't more "mature" than other people, you are just... wiser, I guess would be the closest meaning. And wise people all know that being considered "mature" is another word for "REALLY BORING". In other words, I advise tooling around at maximum retardancy.
As for me, I frequently switch between personalities. I can go from a 4-year old at his birthday party to a 30-year old bored nihilist to a 17-year old anarchist. And I'm only 15. I can't wait until I'm older and have more viewpoints. Gotta catch 'em all.