Every campaign is unique. A friend based his campaign on the Chronicles of Naria and no one noticed, we were all bemused by a serious, somber Father Christmas needing help.
Another DM determined that all red Will-o-Wisps were good and helpful creatures. They became ubiquitous in his campaign and even had their own sound effects. After a while, we all noticed that they were the Red Spots from the 7-Up ads.