Adolescent or Adult?

I'm 18 years old and I am stuck in limbo, that of adolescence and adulthood. Yes, I have to work to pay my bills and even be responsible at times and I feed my cat without being told to. =] I'm being facetious but I hope you get my point. I'm legally an adult and I'm expected to act like an adult, though on many occasions I'm still treated like a child while dealing with my responsibilites and my maturity. When did you realize that you were an adult in not only your eyes, but others?