Always playing the class that is overpowered at 1v1 pvp. This...habit started a long time ago in TBC when I was camped in Quel Danas by some asshole and there was not a damn thing I could do to fight back because he was playing a feral druid and those were sick in TBC when they could switch to bear and do as much damage as in cat while tanking you.
I swore I will never allow this to happen again.