I once was flying with my boss and we were sitting next to each other in our seats. We were both about 6′ 2″ and 215 pounds and in good shape. A guy came up to me and told me that I was in HIS seat and he demanded that I move. I checked my ticket and sure enough I was in the right seat. I showed him the ticket but he showed me that he also was assigned to that seat and that I had to move. I started laughing and told him that he definitely was not big enough to make me move and I was staying put. He stormed off to talk to a flight attendant and I never saw him again.