Once upon a time, an evil lord ruled over a small village. After deeming old people useless, he banished all villagers over 71 to the mountains to live out the rest of their lives.
In the village, there lived a farmer and his mother, who had just turned the dreadful age of 71. Not being able to send his mother away, the farmer hid her in his house, risking both of their safety.
Over two years of peace later, a lord on the other side of the mountains threatened to take control of the village unless they could solve an impossible task. Afraid of how the new ruler would punish him and his mother for disobeying, the farmer searched for a way to do the task. His mother, with all of her years of experience, was able to figure out all three of the impossible tasks, saving the village. The lord realized that old people were valuable, and the law was broken.