I think it has something to do with our fragile self esteem, we want to always be right so we will not be judged by others, and so we can feel good about ourselves. I think it's quite normal, we all do it to a certain extent, but it's also a trap, because we avoid situations in which we might make a mistake or be wrong and it also causes a lot of friction with others because everyone else has to be right too. How much time and energy do we spend trying to prove we are right?
I have been thinking about this a lot lately. I have had some experiences in the last year that were very painful to me. It forced me to think about myself in a different way. I came to the conclusion that I am often wrong, in fact sometimes I am an idiot. Of course this is not news to anyone who knows me, lol. But accepting this and seeing that it doesn't much matter has been very freeing.
I think this is why you get so many flame wars on the internet. People will argue to the death before admitting they might have been wrong. It's why trolls flourish, they know how to push people's buttons and will keep doing so as long as people will respond to them. I find lately that I can just let it go. So what if someone criticized me or a post I made, so what if they are completely wrong, I can accept it and see that it makes very little difference in the overall scheme of things, I don't have to waste time proving anything.