If I had to respond to the question, “What is unexpectedly interesting?”, a good candidate for an answer would be, “The history of mail.” A quick dive into the unfathomable depths of Wikipedia, beginning at “mail” will take you to “cursus publicus”—the Roman, state-run courier and transport service—pigeon post, uniform penny post, “Örtöö”—a supply point employed by Genghis Khan and his descendants—and other delightful destinations.
In fact, in many stories with a fantasy or historical element, the use of relay points to transmit a message (or a person) is prominent. A generic example: a member of the peasantry uncovers a plot to assassinate the King. But said member of the peasantry is more than a day away from the Capital. So he steals a horse and gallops through the night, avoiding sleep and switching mounts at various waypoints once he has exhausted the mount’s energy. At daybreak, he thunders through the city gates and directly to the palace, leaping over the guards that try to prevent his entrance. He finds the doors to the throne room barred, so he rears his stallion which kicks the doors open. They fly off the hinges and, still on horseback, he rides into the room, rises in the saddle and with one hand launches a knife at the assassin seated beside the King. It strikes the betrayer in the heart. At this point another messenger arrives, telling the king of the treachery just in time for His Highness to watch the last droplets of life drain away from his would-be betrayer.
This system of messengers and relay points is significant because it is an uncanny metaphor for how we live our lives. We begin at Point A. We select the mount that seems best and we ride it, as hard and as fast as we can. When it is exhausted and it has carried us as far as it is able, we abandon it and select another, which takes us further. We do this until we reach our Point B, our preferred destination, or until we die—whichever comes first.
Taking an abstracted view of this process, it is possible to say that our past is a trail of carcasses, of activities and avenues that have been exhausted and-or abandoned.