I was thinking of a Southend Congress, 4 days over Easter. The Major section was up to 180, and I would have been in the 140s, drawing a much stronger opponent in the first round. The time limit was slow 40 moves in 2 hours and then a further 20 moves in an hour. I misplayed a Caro Kann and ended up defending an inferior blocked position in the trenches to a what looked like drawn endgame a pawn down after 60 moves. We adjourned again, to replay in the evening. We turned up and my opponent offered a draw.
I was fatigued for the rest of the event. I won one game where I confidently played a pawn and immediately realised that it could be taken without penalty. I wandered ff in disgust to look at other games, periodically returning to see my opponent staring at the position. They took about 30 minutes before declining to take the pawn. Afterwards I asked my opponent why they didn't take the pawn. "I couldn't see any reason not to, but you'd played it so confidently that I assumed there was a reason."
It gave me tempo and position and I didn't look back.