I heard a joke when I was a child. Who can tell me what this joke is about?

The county magistrate will punish fools, so everyone knows that the answer of 28 is wrong. He is a fool, but there are people more stupid than him, that is, people who know the answer and are still arguing, that is, 2 1. When you meet these idiots, just ignore them, but the whole person has been playing all day, just an idiot. Who will you hit if you don't hit him?

The meaning of this joke is not to argue irrationally for unnecessary arguments, but to learn how to deal with problems.