I was wondering if someone would spot that! Yup, it's largely a Norwegian-American thing... my dad was from a ethnic Norwegian family in the upper Midwest. Funny enough, in America it has a somewhat expanded definition compared to how it's used in Norway. It's apparently a less common thing in Norway as well, much like lutefisk (which is whitefish cured in lye to preserve it)... sure it originally came from Norway, but much of Norway has largely moved on and it's the Norwegian-Americans mostly keeping it alive. Which is kinda cool in the case of uff dah, but not so much in the case of lutefisk (which should be considered a crime against food and humanity in general...)