If you take note, you will find that a significant majority of people around us tend to show that they are experienced and knowledgeable. When it comes to a topic, they will keep on talking about it without listening to the view of others. If encountering a subject or an event they really haven’t referred to before, they still never forget to plug in a word: “That’s it, I knew.”
As a matter of fact, no one will consider a person as know-nothing if he/she keeps silence or has little comments on some matters. Sprouting is not a way to prove a person's wisdom and wide learning, but sometimes it can create an opposite effect. Just as a saying "Deep rivers move in silence, shallow brooks are noisy".
So, I want to say, please be quiet, appropriately, maybe, you will gain much more respect from people around you!