The original painting is based on a fable about acceptance:

"A man named Sei Weng owned a beautiful mare and one day this beautiful horse disappeared. The people of his village offered sympathy to Sei Weng for his great misfortune. Sei Weng said simply, "That's the way it is." 
When the lost mare returned, followed by a beautiful wild stallion  the village congratulated Sei Weng for his good fortune. He said, "That's the way it is."
Sei Weng's only son, while riding the stallion, fell off and broke his leg. The village people once again expressed their sympathy at Sei Weng's misfortune. Sei Weng again said, "That's the way it is."
When war broke out and all the young men of the village except Sei Weng's lame son were drafted and were killed in battle. The village people were amazed as Sei Weng's good luck. His son was the only young man left alive in the village. But Sei Weng kept his same attitude: despite everything, he gave the same reply, "That's the way it is".