You had just moved to your new house, you was out in your yard after a long day of loading in your furniture into your house. Then, over the fence, you see a small boy in your neighbour's yard. He was just swinging on a swing in an almost rhythmic motion. You assumed it was just some kid having fun so you stopped looking after a couple seconds. However, hours later when it is now evening time, you see that same boy swinging still. It's been hours, why is he still there?