Rude people is my #1. I say they have OOO disorder.
Oblivious
Of
Others. Those people that will just cut you off, whether it's with a grocery cart or a 3 ton SUV

, like their time is so much more valuable than yours and YOU can wait

I used to just take it and try to be the "bigger" person, but OMG I got so sick of it that now I just stare them down, say to them "RUDE much?!?!" and then get in their way. Except when it's a 3 ton SUV, I let them go first out self preservation