The adage “silence is smartness” is actually not true all the time
When we engage ourselves with confutation in different matters eventually it enhances our minds. You will definitely know what is incorrect with your ideologies and something you need to broaden. Accepting the value and scrutinizing the opposing perspectives will help your understanding among things.
People have different perspectives, grown up in different environment, the way we see things are different, our will, our thoughts about what we observe, different preferences and ideals.
Share your knowledge and learn from others, socialize with other people in a possible nontoxic and productive way.
(

deep-english words)
confubulation = a formal discussion
ideologies = set of ideas
scrutinizing = examine something in a critical way

The quote silence is smartness, but to comprehend it with my own perspective, I think it is not meant like what you think it is. Yes we learn from socialising, experience and such, that’s a way how we adapt things. But to oppose your argument, at least I’m quite confident that I can validate the quote as being, “those who don’t say much likely has the more knowledge, and those who show off more are one being too full of themselves.” In my own perspective, I would rather accept it like this because it is inscrutable indeed that we do learn from doing actions and silence wouldn’t really help. But to augment this discussion, I would like to take this is a more deep meaning quote and more deep wisdom.
There is one more thing. Smartness isn’t associated only in your knowledge. It does also correlate with how you bring yourself to certain circumstances. Silence is powerful, I can verify this after one realisation. If a stranger asked you suspiciously, it is way too smart to not answer it rather than helping him fulfill his motive. Also the fact that silence can help us think more deeper, I will then insert certain circumstances such as planning a decision. Like what they say, think before you open your mouth. If you have no idea about something, it is more smart of you to remain silent. That’s how I perceive this quote. I based it upon my point of view on why silence is also a type of smartness.Silence is an answer, silence is too much that we can’t comprehend it. Thank you.