I hate it when parents expect their children to have been born automatically knowing certain things, and if they don`t they must be a bad or slow or stubborn child. Or the parent expects someoen else to have taught the child, and if the child doesn`t know because no one taught them, the parent assumes it`s because the child was taught but that the child is slow/stubborn/bad. I also hate it when the parent only explains to the child in a way the parent would understand, and if the child doesn`t understand because he has a different way of learning, he must be slower/more stubborn/ a worse person than the parent was/is.