It takes a long time to achieve competence approaching mastery with bushcraft and primitive living skills. There are so many different things to learn, and real learning can’t be rushed.
Tomas Johannson, a director of the Institute for Prehistoric Technology in Sweden, has calculated that would require twelve years of schooling today to learn enough to become a stone-age person.
(From the book Simple Life “Friluftsliv”- People Meet Nature by Roger And Sarah Isberg, p. 183)
I think it’s interesting that the number quoted is 12 years, and our education program through high school is also 12 years.