After years of watching and teaching lessons, and then teaching people to teach lessons, and then watching that, I can observe that many teachers make the same mistake. It is incredibly common, and at times it almost appears to be the default. The most common mistake teachers make is this:
They wait for misbehavior to occur and then they react to it.
Why? Usually they often haven’t had much training in how to handle behavior. Teacher preparation in this area is often very light touch (or worse, sometimes impractical), so new teachers can be forgiven for thinking that it isn’t