It’s always fine to not know the right answer. But if the right answer is not important, it’s not fine not to double check. That’s not very cool.
It’s not fine to sit and double down on your ideas when you may be wrong. The cool thing to do when you’re challenged is to say something like, “Oh, I hadn’t thought of that. I might be wrong!”
That simple pair of sentences makes you so much cooler. People like to work with that person. People don’t call you arrogant. People don’t think you’re a jerk. And when you’re right? People don’t think that you’re going to be all gross and conceited about having been right.
When you double down, when you refuse to concede, when you refuse to look up or look at evidence, when you gloat about being right, when you pout about being wrong, you’re not very cool.
In general, nobody wants to work with that person. Be cool. Admit your mistakes, be open to being wrong, and just be cool about it, dammit.