"What is my intention in engaging in this discussion/debate?" is something we ought always ask ourselves, I believe. If my intention is to look smart by embarrassing someone else, at least I should be honest about it in my own head.
I admit it, there are times I think someone is such a douche for the arrogant way he frequently bullies and mocks others that I will jump into the fray just to shut him up. And that can be a lot of fun! :-)
But in the end, sincerely, I just want Truth. Period.
After all these years I have examined-and-dropped SO many beliefs that acknowledging my errors is easier and easier to do; I am less emotionally threatened by them. In fact, since everyone should want to be right, the quickest way to get back to "right" is to admit a mistake, an error, and adjust accordingly. Like admitting that you just engaged in the Fallacy Fallacy if you did.