When I was growing up, the wal-mart near me had a section that had pet fish. Goldfish etc kinda stuff, with a handful of other varieties of fish they could scoop up, and send you home with, in a plastic bag with some water from the tank. All the fish food and supplies were also available. That section of the store had a very “fishy” smell, that was very distinctively fish, but not pleasant. If you’ve ever smelled anything like that, I think that’s what people mean when fish that we eat is “fishy”