Comment by ironmagma

They very much can. Have you ever walked into a classroom and seen the ancient runes left on the board from a more advanced class, wondering how any person can possibly understand all that and wonder whether it was possibly even scribbled as a joke? And then two years later, you realize that you have learned and mastered that very content you saw on the board that seemed so unachievable. Many things seem unlearnable, but given the right conditions (teacher, home situation, motivation) most people are surprised by the scope of what can be learned by an average person.