That reminds me of a story of a friend who was a helicopter mechanic in the Australian Army. He had finished everything he needed to do and said to his supervising officer he was "done for the day" - He ran laps for the next 4 hours in the tropical heat - he was never done for the day again. =)
I was lucky and joined the army when I was a little bit older than the other recruits. I already knew a lot of the games that were being played in training. We would have to clean weapons and the drill sergeant would tell everyone to bring their weapon up when they thought they were finished. I knew that no one would ever be finished early. They had budgeted a certain amount of time for weapon cleaning and we would use all of it. After my weapon was clean, I sat and pretended to clean while others went up and got yelled at and "smoked" (made to do exercise) for thinking they were done.
Knowing what game is being played is usually a good start to surviving a game. In military training the drill sergeants mostly played a game called "You lost and I'm going to show you why" and you just have to get through it.