Silence implies understanding. If you don't know something and don't ask a question, you're saying "I don't want to learn". If you're silent too often, even if you know the answers to your questions, then others may stop trying to talk to you altogether. You may never get the opportunity to decide what you want to learn.
Some questions serve to teach others, especially in debates or discussions. This is commonly known as the Socratic method. By remaining silent, you not only condemn yourself to ignorance, but also others. By not asking questions, you're saying "I don't want to teach."
Teaching too much can be a problem for some. These people are unable to let an incorrect detail or fact persist. You've probably been corrected by one of these overly precise teenagers or pricks. It seems especially annoying if they're younger than us. We know better because we're experienced!
Except, being overconfident about our own knowledge puts us in the same shoes as those with less experience. If we know better, shouldn't we ask questions to teach them? When we demand respect to the extent that it halts discussion, we're crippling thought. We miss out on the opportunities to teach and to learn. We're saying "I embrace ignorance."