I'm 16.
I look about 15 by my face only, but as soon as people see my height I look more like a 12 year old.
Honestly.
On the other hand, I act like a 40 year old man who's realised he has no fun in his life anymore. Basically, it takes A LOT to make me properly come out of the moral, introverted, slightly egotistical but relaxed person I am and into this outgoing person.
But I really do not look, nor do I act, like my age.