The thought behind that is that we talk too much sometimes. There is a time to talk and a time to keep silence (Ecclesiastes 3:7 Ecclesiastes 3:7A time to rend, and a time to sew; a time to keep silence, and a time to speak;
American King James Version×). When we were children, we realized adults were smarter and knew more than we did, so we usually listened. Adults ought to come to the understanding that we still do not know much, and it is important to listen. James was writing to adults when he stated that we ought to be swift to hear and slow to speak (James 1:19 James 1:19Why, my beloved brothers, let every man be swift to hear, slow to speak, slow to wrath:
American King James Version×).
Talking out of turn or just talking too much creates problems for us. Listening and thinking before we speak saves a lot of apologies and embarrassment and spares us from spitting out a lot of flies. Less speaking, fewer flies—that makes sense.