You become an adult when you no longer need support from your parents or the government.
So farmers who take advantage of subsidies in the U.S. to keep their farms going aren't adults? You should tell them that. To their faces.
Do you lose adulthood when you get a pension then? Or when you get sick (in countries with functioning healthcare systems)?
So farmers who take advantage of subsidies in the U.S. to keep their farms going aren't adults? You should tell them that. To their faces.