I sat next to a pretty large woman flying home from Maui. I was in the middle between her and my very broad shouldered husband. She wanted me to put the armrest up. Unfortunately I have bad shoulders - a combo of rotator cuff issues and rheumatoid arthritis - and I told her that I had to rest my arm on the arm rest. It was a small battle for the remainder of the flight. We shared the arm rest which was kind of awkward but whatever, but when I used the loo, the armrest would be up when I came back and we'd start the discussion again. Nope, my shoulders are still painful, still need the arm rest. Ugh.
Oh well. And I love chatting with folks on the flight (But totally respect the ones that don't want to chat - it's obvious). I wish there was a section for the chatters, lol. I would sit there for sure
Oh well, it's essentially very expensive public transportation. You just have to roll with it.