Rage.

I get irrationally angry when I see people use the word "clearly" to describe something they consider to be fact rather than opinion. e.g. "I am clearly right". It's one of very few annoyances left over from my time involved in my online hobby where we'd frequent message boards and discuss various, related topics and people would use this all the time to put forward their opinion as fact, and it's something I've started noticing again an awful lot recently. Ooooh, I'm getting angry even now thinking about it (and all the fuckwits from back in the day, too).