Here's mine....
All week I've gone swimming. There are 3 lanes open at my pool: slow, medium and fast.
I get immensely frustrated when I see people who *think* they are fast, swimming in the fast lane. Dude, if my breaststroke kick beats your freestyle wtf are you doing here? Move lane! Also, people who obviously relaize that you're faster than they are because you leave them a half-pool's advantage so you're not in their toes all lap long, you still catch up to them and at the wall, they don't let you pass...GRRRR.
I just feel like telling them ''Buddy, you have absolutely nothing to prove. You're slow. Move out.'' Respect the lanes and the swimmers, please.
What frustrates you?