Azadelta is the only one who looks at what I'm wearing. And he has often caught me out wearing my PVP gear, or my Chef's hat (which fortunately now the risk of that is a lot less since I now show my helm).
However, last night I didn't realise I spent the whole raid night healing with my Blessed Medallion of Karabor on. And the only reason I realised that was that I had my Ethereal Footfalls made yesterday and I was trying to figure out why my haste was so low, and whether I would have to put haste on my boots. It was then I looked at my neckpiece...and that damn neck had been saved into my healing set! Which means that I have been wearing that since I was doing Black temple... last week. OOPS.
It wouldn't be the only time. A few weeks ago I was raiding with Belinia and I realised later that I had done the whole raid with Loop of the Kirin Tor on....
I guess that's the problem with carrying around all these items to use as multi hearths!