Back in Vanilla WoW, I played a human warrior that I imagined was a survivor of Lordaeron. He'd actually been in the group that left with Jaina for Kalimdor - he'd seen Arthas preparing to purge Stratholme and he wanted no part of it. Killing them after they turned was regrettable but necessary - killing them before just seemed like madness, the kind of madness that eventually destroyed the entire nation. First you tried to cure it, and if that didn't work, then you did what had to be done. As a result of my little experiment in backstory, my character had been all over Azeroth by the time Wrath of the Lich King was announced, and had even traveled through the Dark Portal to an entirely alien world. He was rootless, because his home was effectively gone forever.
Since then I've switched to a draenei, so I've actually been ever more places. Just counting from when he woke up on Azuremyst Isle, I've been up and down Kalimdor, the Eastern Kingdoms, Northrend, Outland, the Elemental Planes of Deepholm, Skywall, the Abyssal Maw and the Firelands and now Pandaria, and soon I'll be going to another reality altogether. I've logged a lot of travel miles, I've been a lot of places. I often wonder what it's like when he goes back to the Exodar - does he ever consider settling down there? Or does his wanderlust motivate him to ever explore, ever head over the next hill, to see what's out there?
Okay, it may also be the loot. It's probably mostly the loot. But what about you? Why does your character keep going over the horizon, and how does she or he feel about where they came from?