I saw the trailer for a movie and was struck by a line in it. It really captures how I feel, and have viewed things for at least 20 years now. Rather than try and quote it, I'll twist it to match myself:
I feel like I'm a kid pretending to be an adult most of the time
The truth is I don't really feel like an adult. I still feel like I did when I was 18 and honestly I don't want to "grow up!"