The essence of adulthood is not age, or seriousness, or responsibility. It is not employment, or voter registration, or the right to become publicly inebriated on a Wednesday night. Rather, it is having a washing machine that doesn't require quarters to run.
I think the washing machines that run on little debit cards don't qualify one for adulthood. Nope: only the ones that run on plain water and soap, for which the marginal cost is only a blip in the electricity and water bills.