Hey, I'm 75 and at times I don't feel like an "adult."
However, one week after graduating from high school at the age of 17 I moved out of my parents home in a small New England town and had my first job in Boston. I paid my own bills, worked to create good credit, and took care of my own health responsibilities. At the age of 28, I moved cross country with no job and no apartment waiting for me. Within a week I had both.
On the flip side, I didn't learn how to drive or own my first car until I was in around 35. I'd always lived in cities with good public transportation, so there was no need to learn to drive.
I worked hard and wisely to give all my employers full value for my salaries. Because of this, I was able to retire at the age of 60 with no outstanding debts and a home with no mortgage.
Maybe like the earlier poster I'm an old fart, but I have little sympathy for people expecting life to hand them everything.