That’s not in any way a sign of weakness. It’s better for us to assume that you are wise than for you to speak and refute our assumption.
You know, I find it bemusing when I see videos of Journalists/interviewers who ask questions from random people on the streets and rather than for the interviewees to answer to what they know and say “I don’t know” to the things they have no idea about, they often don’t get to take that noble path. They try to wing it. In their world, that’s how to be smart and unfortunately in that way they exude confident ignorance, without knowing. It’s a torture to stay around such people who know nothing and yet are not aware. People who are so sure and yet so wrong.
At the base, they try to muddle up their ignorance in a lot of verbosity, superfluity, and grandiloquence thereby communicating their nuisance without knowing.
If you know your stuff clearly, you will speak clearly & understandably. You will keep it simple. And you will come across, dignifiedly, as someone who has clear thoughts and has a good grasp of what he’s talking about.
In the words of Albert Einstein, if you can’t explain it to a six-year-old, you don’t understand it yourself.