Kaze ga fuku to Okeya ga moukaru
The wind blows and the bucket maker prospers
The logic goes like this: the wind blows sand in people’s eyes, turning them blind. They naturally learn to play the shamisen, a traditional 3-stringed instrument. The strings are made from catguts, so this new wave of blind musicians decimates the population of stray cats, causing the number of rats to surge. The rats chew out the bottoms of wooden bathtubs, making more work for the okeya. Therefore, in a strong wind is a boon for the bucket-maker: the consequences of one event are far-reaching and unpredictable.
Japanese is full of these kotowaza, old sayings. I study the language with elderly volunteers, who as you might expect are ripe with such expressions. Somehow an explanation of causative verb forms spilled into this strange chain of cause and effect. I like how the entire middle portion of the chain is left unsaid, inferred by only the first and final link. I wonder if most people today even remember why the wind favors the bucket-maker.