Have you ever stopped to think about how many times you react negatively to your kids in a given day? You may find yourself criticizing far more often than complimenting. Getting kids frustrated about somethings ir jot showing them the importance of it will make them lose interest in things they ought to know.
Most times according to my observations so far, kids mostly wrong about such saying, cause everything they are meant to learn while they are young turns out to be useful later in future, if not for them, but for their children unborn, friends or any other person. No knowledge is a waste.