Interpret the subject as you please. I can probably rant on and on about people I know who have more camera than they need and share some funny stories. However, I too fall into this category.
I cannot claim to use every single function of my 5D3s' capabilities. For example, I've never programmed my custom shooting modes... I probably should. There are also a few features I've played with, but haven't really utilized - e.g. My Menu, double exposures, lens microadjustments, even AE lock... list goes on.
- My #1 offense: Video.
- My #2 offense: Off-camera flash.