If you ask most Catholics why we eat fish on Fridays during Lent, you will likely hear that it's meant to be a kind of sacrifice. It's kind of funny if you think about it: Some of Jesus' closest pals were fishermen. Fish even became a symbol used by the early Christians to safely communicate with one another and signal meeting places. Its place as a Catholic dinner staple seems more like a statement of identity -- we're Catholics; this is what we do -- than a hardship. As authors Brian Fagan and Michael Foley have shared, the actual history of our tradition of eating fish on Fridays is pretty crazy and involves the Vikings, King Henry VIII and, eventually, the Filet-O-Fish. But a main component of the practice for most Catholics has long been that a meal of fish displaces the more decadent options meat provides. It represents a form of asceticism or mortification. It's "a simple meal."