@marshray @cwebber "received wisdom" it sometimes is used to suggest something is true, though, it only gets at the untested nature of the "wisdom".
I do have a better story example though. A cook who always cuts the end off the roast, says she does it because her mother taught her that way, because her grandmother taught her mother that way. They thinksit's needed for the recipe, maybe it makes it juicier? But when asked, her grandmother says, "it's because the roasts we buy from the shop didn't fit in my oven".