The other day I heard a story about a man who decided to kill his elderly father as the old man was too weak for productive work and the son considered him to be a burden on himself and his own kids. He built a large box out of wood. The box had wheels and door with a padlock on it. He shoved his father inside and locked him up. He wheeled the box to the edge of a cliff where he intended to toss the box on to the rocks a hundred meters below. As he was about to send it over the edge, his old man piped up from inside.

"You know you can go ahead and toss me off this cliff, but you should really keep the box. Your kids may have need of it when you get to be old like me."