This is an old tale. Various versions can be found on the internet.

We recently took a trip to Merrie Olde, and we enjoyed it very much. The service was good and the food was much better than we had been told to expect. We ordered at a small fish and chips shoppe in the English Midlands, and we couldn’t believe the size of the portion of fish that came. It was unbelievably large and it was even more delicious.. It was truly wonderful, but how could they make money giving so much fish at so reasonable a price? An English friend explained it. “It’s the piece of cod which passes all understanding.”