It was the person in front of us and short answer, we moved right after take off but there was pax flight rage about hour 10 into the long haul.
The long answer is:
I think this was the last Y flight we ever took (joined AFF soon after, been flying J every since except for one flight) and took our seats and the person in front just seemed off to me. In the few mins were seated, she stood up, down, up, down, walked around, sat, up, sat again and I said to hubby I cant handle 14hrs of her so I was going to move if I could. Doors closed and I spied 3 empty seats about 4 rows behind us. Yes, near the galley and toilet but the idea of the toilet and galley curtain being moved annoyed me less than this person.
About hour 10 and it was on between this woman and the old guy in front of her. He yelled that he politely asked her to stop kicking his seat at numerous times and had reached his limit. There was yelling, fingers pointing, both spouses also up and yelling, SQ FAs came running from all directions.
About 30mins later I saw the mans wife waiting for the toilet and I asked if she and her husband was OK. I told her that I moved away from the woman after take off as she had red flags that she was going to be annoying. Apparently she was putting her feet on the back of his chair and pushing and every time she got up, she would leverage herself on the back of his chair. I think the wife appreciated hearing me saying something and it wasn't just her husband/her that was annoyed by her.