For one, everyone develops at a different speed, making the magic 25 number rather reductive. “Some adolescents take on adult roles really by the end of their teens, other don’t take on adult roles until their early 30s,” he says. “Talking about adolescence is best done by thinking about these processes, than by thinking about chronological age, which is a much less important marker at this age.” And people also change dramatically through the course of a single day. (As anyone with their own teenager knows, adolescents in particular are capable of staggering range.) While they may act foolishly in one moment, they can present as an enlightened being the next.