Odysseus is trying to decide weather or not to kill the Cyclops. He is sleeping and vulnerable, but there is a heavy stone blocking the door. Odysseus decides not to kill him so that the Cyclops could move the stone.
Odysseus and his men were trapped in the cave. The Cyclops rolled a rock in front of his cave to trap them. When the Cyclops left and came into the cave he rolled it back.
Strength does not always beat brains. The Cyclops was stronger then the men, but the men were stronger. The men rode out the cave on the Cyclops' flock of animals.