I quite like this study on de-escalation online. I myself have learned to not care about whether or not people forgave me for being wrong or instead just assume they forgave me for being wrong. If I think I am actually wrong i'll say it and then ignore any further replies to the post. In the case that I simply do not agree that I'm wrong, I do not apologize. I "pithily" re-iterate my opinion/disagreement/argument and why, then ignore any further responses. Keeping track of everyone else's petty beefs with me online is not worth the effort. shrug

As a side note: I do not believe in grudges. So..I do not stay mad.