The implication of saying that there are things children must learn to study is that the children may not want to learn them, because they won't know that they are valuable until later. But if you can't enumerate them all, then how do you know, when you are forcing your children to do one of them, that you are not preventing your children from doing another? Also, if you can't enumerate them all, how do you think the children are going to learn the ones you are unable to enumerate? In fact, I believe that not only can you not enumerate them all, but you can't KNOW