Probably only once to me, to be honest. I've learned to steer clear of the lock-bait.
I have likely made about 500-1000 posts that I never sent, because it was the verbal equivalent of ripping someone's head off and dumping in their throat. Or it just didn't really make any sense after I typed it. Or it didn't add anything to the thread, on second thought. So there were many times I'd type and type and think, type out a wonderful rebuttal, research, and then read it...and just say to myself..."no, that sucks", and press the back-one-page button.