Grinds my gears
You know what really grinds my gears: Fans at sporting events.
I realize that everyone is entitled to their opinion; however, I would much rather listen to some than others. Case in point, at the last Rams game I was sitting behind this yahoo that thought he knew pretty much everything there was to know about football, I am sure you all know the type.
When the refs made a call he would instantly agree with them no matter what. Exhibit A: A Rams player was brought to the turf by an opposing player after the whistle had blown. As soon as this happened Mr. Know-it-all in front of me goes "well that's a penalty, they have to call that, that was clearly a penalty!". Turns out the refs do not call anything, meaning that according to them there was no infraction on the play. Instantly, Mr. Know-it-all goes to his buddy (who is probably ready to drown his sorrows in booze by now) and says "That was the right call, there wasn't a penalty those refs are good, I knew they wouldn't call that."
Really? Did that just happen? Did you not just say.. you know what, whatever. Not everyone can be right, and the refs definitely can't be right all of the time, unless you are the guy in front of me.
Basically, moral of the story, if you have something to say then say it don't yell it for the world to hear. If you are certain about something, say it to your friend so that they can be impressed with your knowledge. If you think a call is questionable then keep your opinion to yourself and you won't look like a complete idiot either way.