You push the boulder up the hill. It is hard work, and as you reach the summit, you trip and lose control of the boulder. It rolls back down the hill and you tumble after it. You stand up, and find yourself back where you started. You can see a bunch of grapes, hanging down in front of you, easily within your reach. To your left is a large boulder, which really needs pushing up the nearby hill. Will you: Eat the grapes Try pushing the boulder back up the hill again