One thing that hasn't been mentioned yet: The OP was one of the last to board and had a window seat. This required at least one person, probably two, to get up to let them in. Then those people had to get up again to let the OP out and the tradee in. Not to mention being "talked across" when the OP and the FA were communicating about the seat trade. One, or probably two, more people had to get up to let the OP into the tradee's seat, then up again when the OP wanted water, then again to let the OP back into their seat. All within a relatively few minutes at the beginning of a transcon. I do hope that everyone got to remain seated for the remainder of the flight.