Maturity

..should not be measured by how un-child-like you look and act. Dressing up casually or in a not-so-grownup way, moving in a care-free manner, and still liking 'kiddie foods", 'kiddie shows", and understanding "kids talk" doesn't make you immature, unless that's all there is to you.

Maturity is in knowing (and doing and standing up for) what's right, whether or not you are going to gain from it. It's in making "grown-up" decisions basing on what's right and honorable, taking "grown-up" responsibilities, being true to your word, understanding that you are not the only human being on earth and everyone matters as much as you do, and living your life the most meaningful way you can.