I only mention it here because one of the comments, by someone called "The Prof.," articulates my own sentiment so accurately and effectively. With due respect to the author, whomever (s)he may be, here it is:
I teach English to high school students who simply refuse to read 25 pages per night of an assigned novel. In choosing to fail, they feebly hide behind a shroud of not understanding the text as a defense for not participating. They make no effort. It is shocking how many parents and administrators fall for this lie before turning to me for an explanation of what I am doing to help the poor child.
As I have written before, students who claim that they "don't understand" a text are really only expressing wanton intellectual laziness. For one, it is impossible to "not understand" something written in your own native language; it's just not possible. I know a lot of people, especially students and parents, don't want to hear this, but it's the truth and it is ultimately, logically, inescapable. For another, "understanding" in this sense is not a binary inquiry; it's not a yes-or-no question. Saying "I don't understand the text" is just another way of saying, "I want you to do my thinking for me, because I don't feel like doing it myself." (Either that, or "I don't want to do the work that follows the reading, and if I can't do it I don't have to do it.")
A student will claim that he "doesn't understand" a text because he has no incentive to understand a text. He prefers to "not understand" it because if he does understand it, he will have to do his work and participate. And he knows that all he has to do is claim that he "doesn't understand" it, and he will be absolved of all responsibility for participation and production of class work.
Children don't know things because they are not expected to know things. They don't understand things because they are not expected to understand things. They are excused, forgiven and absolved by adults; first by parents, then by administrators in response to parent complaints. I can't recall how many times over the years I've heard other adults tell me, "You can't expect kids to know that," or "You can't expect kids to be able to do that."
THIS is what is destroying public education.