This is not an ESO issue, which is why I'm posting here as opposed to the bug forum.
If you did not buy ESO from Steam, and you use a controller, shut Steam down completely before playing ESO. If you do not, there is an issue where every button you push on your controller will activate a secondary keyboard key. This often causes issues such as accidentally attacking NPS's, or the inability to open the menus, and many others.
It took me an embarrassingly long time to figure this out; 4+ days before it occurred to me that Steam may be the issue. I don't know if this problem is well known, or obscure, but I didn't see anything on it, so I decided to post this.