I can tolerate idiots. I really can. I've occasionally been one myself and everyone's entitled to talk out of their posteriors at some point or another.
What I can tolerate much less is everyday aspects of what I call DRE (the Donald Rumsfeld Effect) where someone can look you in the metaphorical eye and tell you something that you know isn't true, but that you have no choice but to go along with despite their rewriting events and you resisting the inclination to shake them and say 'Huh?' many times in quick succession.
It's not the 'because I say so' parental variation which sometimes comes in handy for moderating and, well, parenting; it's the 'I know I said I agreed with you and you've gone off and done stuff based on that agreement, but now I'm explaining that I really didn't agree at all and now YOU have to fix it...' variation.
If people said what they meant and didn't expect you to have some inherent mind-reading ability about the likelihood they'd flip-flop the minute you left the room , life would be much more tolerable.
Sometimes I feel like doing 'a Wesley Gibson' (a la the character in WANTED, which I hope to see in London early Thursday) but it usually ends up more like doing a 'Dilbert'.