I took the wrong seat one time (took 1C instead of 1b), I had done a SDC and looked at the wrong boarding pass and the guy was a complete DB about it. It was a CRJ with no first class and only row 1 was C+ from AGS to ATL and it didn't have the extended bins on the a/b side and he started complaining to his wife that he had to put his bag towards the back and if I would have sat in the right seat he wouldn't have had to have dealt with it. He should have realized that my rollerbag would have gone in the same bin regardless LOL. Myself and one other passengers were the only ones that boarded with PREM and him and his wife were gate licing. He was complaining really loud to here about how it was bad enough that diamonds weren't paying for those seats and it was unfair we were allowed to board first and take a wrong seat and his bin space LOL.