There is a maxim of unknown provenance that goes something like this:
Better to remain silent and be thought a fool than to speak and remove all doubt.
It's quite true. When you don't know much about a topic, the best way to expose your ignorance is to speak up.
The implied part of the aphorism I disagree with, though, is that it's necessarily a bad thing for others to see your lack of understanding.
Is it a problem if your goal is to have others think the most of your ability? Sure. But if your goal is to learn and to grow, silence just allows you to hide your ignorance from both others and yourself.
At some point, you will be corrected in your false beliefs, and the sooner that happens, the sooner you'll be more capable and knowledgable in your particular discipline.
So, I'm very glad I have the opportunity to repeatedly make a fool of myself in front of the urllib3 team. Is it uncomfortable? Sure. But I know that I can learn more by discovering myself to be publicly wrong than by thinking myself correct in private.
Of course, key to all of this is to keep trying to follow Wheaton's Law: Don't be a dick.