Something that's annoying the hell out of me lately:
I still see tanks running around in full Strength gear in FFXIV, like they didn't get the memo that SE changed it so their attack power is based on their vitality.
They could be returning players, or extremely casual players who don't read update notes (I don't). I'd just pass on the knowledge.
What truly surprises me though is the amount of BLMs I've partied with for DR EX at 60 who still use the pre-HW rotation. They never pop Enochain nor use Fire IV. Needless to say, it makes bosses last longer than they should.