Here's the story as I heard it at a presentation by the inventor of the Y2K fly.
The Lower Mountain Fork in Oklahoma has an annual one-fly tournament. You can use only one fly for the entire tournament and prizes are awarded on size and quantity. Many of the fish in the river are hatchery fish. One inventive fisherman (the speaker at the presentation) decided to create a fly representing a kernel of corn. The fly was wildly successful and he won handily.
I would have disbelieved him if I had not experienced fishing in Missouri with my best flies for one fish in an hour when along came a local with a spin cast rod, a bobber and a can of corn. He took ten fish (the limit) in as many minutes while I continued to struggle for takes.