Just about eight months ago, I visited a local community's wastewater treatment plant. Maybe eight or so people from our local campus "learning in retirement" organization drove the 40 miles to visit.
We learned that several products are labeled "flushable" that aren't. They don't dissolve well and can clog pipes, especially when there is a mass of them. Toilet paper dissolves well and doesn't cause a problem.
We also learned that the plant has a new robot that climbs through a network of pipes and transmits pictures of what it was finding. The employee who told us sounded quite pleased with the new-found possibility of seeing what the robot finds.
I didn't realize that the mental image of that robot crawling through pipes would strike me and stay with me. Dan Buettner's "Blue Zones Kitchen", about the diet that extra-long-living residents of the world's Blue Zones eat, helped me decide to have many breakfasts of the same cereal, Heritage Flakes. I like them enough to buy a small bulk order from Amazon. A bowl of those flakes, along with banana slices and blueberries, makes a nice and complex network of crooks and nannies, ins and outs. Yet my milk, poured right from the gallon jug, finds its way through them all, every morning!