I need a serious help.

I'm 22 tomorrow and i'm often told I act childish, to be honest it pisses me off sometimes.
but then again, it's just my behavior. 
I'm quite mature when I need to including working full time, paying my own tuition and living expenses etc.
All it matters is if your'e mature where it's needed.
I think being mature is controlling your own ego and being independent.
as for behavior, that's just society's definition... I like clothes that are considered not very mature cause they have elements like ribbons, ruffles and sweet prints.
so what? should I dress in boring clothes or behave very seriously all the time? if I like to joke around and laugh from time to time I don't think it reduces my mental age.
people just have a certain image of "maturity" in their heads, and I don't believe we need to conform to it.