The classes are dysfunctional and meant as a compromise between various groups in a society. But even in some Montessori paradise, a kid will need to have a natural impulse to get anywhere. It's not so much that a kid is supposed to intuit things out of thin air, but rather that the type of person who does well with literature or even approaches it at all will almost always also be the type of person that has already has this natural intuition and motivation. What great teachers can do is lend a spark to the wick, and luckily these specialists seem to magically appear when they are needed to the most, but even the most skilled farmer can't grow wheat out of rocks.