When was the first time you really felt like a grown up (if ever)?
The first time I went drove to another state and stayed in a hotel on my own (late teens, obviously after getting a driver’s license — but a year or more before graduating high school.)
In retrospect, I’d say it was when I was on an airplane headed to Basic Military Training. I left a few days after completing high school classes, and a week or so before our graduation ceremony. That would definitely have been the point at which I had to realize whatever transpired, I was on my own. My problems were no longer distributed between myself and parents or myself and teachers, but it was all on me.
That said, I suspect that as a teenager I would have reported moments long before then, like my first solo out-of-state road-trip. I think a general feature of the adolescent condition is feeling grown up before one actually is in any real sense.
Tiger Riding for Beginners 