"Longest you worked without rest + why?"

Maybe around 7hrs or so? It may not be much, but the thing is that I had to work almost the whole night through.
I was about to show off a game at the school festival, and I had to finish multiple playable stages while not having a dedicated stage editor application; I was using Notepad as the stage builder. I had to work through the night before the event.
Ended up catching the flu after the event, but I don't regret it.