"You are simply not lonely enough when you travel with companions… Spells of acute loneliness are an essential part of travel. Loneliness makes things happen." --Jonathan Raban, Driving Home: An American Journey (2011)

Travel is as much an internal journey as an external one. As we move through countries and accumulate stamps in our passports, we're logging miles. However, a more subtle odometer is ticking away in our minds. Our attitudes and personalities evolve as we see more places, meet more people. Dave, a vagabonder who writes "The...