In my first play, I didn't know we could repair gear until one of my buddies noticed my chest full of broken hammers and she told me where the button was. I simply thought it was "this is a crafting menu, so here's a hammer showing this." I never bothered actually mousing over it to see "Repair an item" as the tooltip.

I wonder how far I would have gone without knowing that if she hadn't told me... Glad to know there's someone as incompetent as I was. :P