I was looking at this site and found this test to see what age you act.
http://www.blogthings.com/whatagequiz/
I am about to turn 18 and I got
You Are 12 Years Old
Under 12: You are a kid at heart. You still have an optimistic life view - and you look at the world with awe.
13-19: You are a teenager at heart. You question authority and are still trying to find your place in this world.
20-29: You are a twentysomething at heart. You feel excited about what's to come... love, work, and new experiences.
30-39: You are a thirtysomething at heart. You've had a taste of success and true love, but you want more!
40+: You are a mature adult. You've been through most of the ups and downs of life already. Now you get to sit back and relax.