Children traveling alone.

Guys who don't wash their gym clothes

You smell like a wet, moldy ass. Thanks for choosing the locker next to me.

Parents who don't drug their children before putting them on planes

Three words: Children's Cough Syrup.
Use it!

The third person that day who asks, "How was your vacation?"

You know, Nancy from the Temp Pool, every second I was away from you was a fucking eternity. Thank god you're here with me now.

Airline stewards who don't enforce the one carry-on bag rule

It's time to teach these jerks a lesson! If I tell them they're being inconsiderate, I'm just causing a conflict. But if you make them check it at the gate you have the power to ruin someone's day and make mine. Come on, flex your authority!

People on planes who hang out in the aisle

Everyone is staring at you, and everyone thinks you're a tard.