I wrote this regarding a different cycle, but they are isomorphous. One ends, the other begins. This is the nature of all things. I'd like to mitigate some of the fear around the beginning year: "apocalypse" stands for revelation, not end of the world (unless we so choose). It is the end of the world as we know it.
It is, simply, the end of a Long Count. Think of it as a trip meter.