We seem pretty similar! I've felt this way for a while as well. I like going to work, paying the bills, doing the dishes, etc. I also rarely get carded -- waiters have been asking me if I'd like to order a drink since I was around 14! I was also always cast as the middle-aged characters in high school plays :P. I wonder if looking older has some weird relationship to this: maybe looking older causes people to treat you subtly differently, leading to more "adultlike" behavior earlier? I have 0 evidence for this though haha.
Perhaps! Yes, I was often asked, "Would you prefer the lounge tonight?" as a teen. I enjoy going to work, organizing and cleaning, reading the mail, making appointments. Also, buying furniture and landscaping gets more exciting as I age! Hmm, that's an interesting theory. My parents were always the "treat your kid as an adult" type - it was rare I felt patronized, and they usually tried to include me in their daily happenings. Were your parents the same? I imagine they would have the most influence on your behaviour and perception of yourself.