Probably one of the better recent examples of mixing two separate subjects from not-normally associated fields, one being rather geeky, and the other a regional-specific reference unique to our neck of the woods. So in other words, a pretty narrow self-limiting set guaranteeing nobody will get it, aside from Dear Readers and True Friends.
Fish wheels are employed by Alaska Natives as a method of subsistence fishing for salmon on both the Yukon and Copper rivers. Aside from their cultural importance they're also really hard to draw, hence the awkward doodle before tracking down some real reference sketches from actual fish wheels, which are scattered throughout the community.
Above and beyond that, there's the standard meme by Admiral Ackbar from Return of the Jedi, which just never gets old.