24 and I think I "Act" my age somtimes (when required)... Not all the time as I still have a stuffed animal collection.. (mostly mascots from my Rainbow girl days) and I still watch cartoons Saturday morning if given the chance.. (of course they're NOTHING like saturday morning carttons from the 80s and early 90's though, why else would they be bringing them back ??!!) and since I still look like I'm 17 no one even questions my (sometimes) childish behavior :D
Last time I was at camp some campers got yelled at by a more "mature" staff member for going in the pool area unsupervised. I had to show him my face, and he was like " oh... whoops didn't see you there ! THANK you genetics for making me the same height as a tall 10 year old. :p

I'm 21, and I'll be 22 on August 21st. Some people say that I look like I'm 17. It's because of my height. I'm only 5'3".