It does make you think about that process, Leonardo da Vinci for example was already training at ~14 due to his father's status letting him train under the reno

It does make you think about that process, Leonardo da Vinci for example was already training at ~14 due to his father's status letting him train under the renowned Verrocchio. We already see several things here: parents with enough resources to seek strong mentors where they cannot be, wanting to foster specific skills, and a kid showing up consistently. Potentially, our extreme infantilization of kids and teens (helicopter parenting, baby voice talking, avoiding responsibilities/recognition of skill, etc) have likely been a huge reason why many are stuck with this "fixed mindset" noted in the article. It feeds into the myth as well, someone like Leonardo appearing in public "fully formed" would seem like he was god-like when you're the same age.