The man with 1,000 Klein Bottles under his house (2015) [video]

Add in that the whole warehouse had to get packed up and moved while things were in unknown locations, each of the million items is unique and owned by different people (some who want their items right now), and it's all still stuck in the moving containers a year later due to red tape.

This is the nightmare I am trying to figure out how to untangle right now.

There is a lot of literature (as well as jokes) in CS about cache invalidation and how hard it is to get right. Well, inventory tracking and warehouse management are actually remarkably similar problems to cache invalidation problems, and you can get all of the same things wrong. But worse. Because unlike cache invalidation, inventory moves via unreliable human processes, has return logistics when you get things wrong (sometimes even when you get things right), and sometimes things just magically disappear.