Guess I'm not an adult since I don't have kids. Never mind that I'm a college grad, have an advanced degree, have been in the work force for 5 years, have been married for 4 years, own a house and two cars...
I feel the key criterion is being either self-supporting, or prepared to be self-supporting (e.g. you're unemployed so you temporarily have to move back in with your parents, or you take some time off to have a baby but could jump back into the work force if necessary).
You don't need to be a college grad to get to that point, but it gets a lot easier if you are
