OK, I was responding to a thread in another forum when I remembered my ex-boss. He really grinds my gears as well as my co-workers' gears. This one will trump all others, I promise
What grinds my gears are people who are cocky and get ahead in life without an ounce of sweat. Some of us spent a lot of sweat and tears just to get where we are today in life. No, my ex-boss has a nice M.O. He was known to chase the Owners' daughter everywhere he worked. Well, when I joined my previous employer, he chased the company owner's daughter and bagged her. After a year, he owns part of the company.
Another 'what grinds my gears' moment is when both him and his father-in-law (owner of the company) starts 'keeping up with each other.' By this I mean: if one has a new toy, the other buys the same toy. The drive similar upscale cars. If one shows up with the latest iPhone, the other rushes out and buys the same. One gets a tablet, the other gets the same tablet. During the company picnic at the boss' home, we noticed that they wear the same slippers and smoke the same cigars. They both own the same breed of dog. Heck, I won't be surprised if they wore the same underwear!
The last thing that grinds my gears is when my ex-boss walks into the office in the morning. He whistles but he can't whistle properly. You know how a half-arsed whistle sounds like. Looking smug and cocky. That drove me nuts! That's it! I resigned after seven long and gear grinding years. I have had enough.