Imagine this...

You wake in an unfamiliar bed that is one in a nightly series of unfamiliar rooms. Relative strangers wake, dress, and brush their teeth next to you in the pre-dawn hours.

After lacing up your well-worn shoes, you strap on the backpack that holds the entirety of your possessions for this multi-week, or multi-month, pilgrimage. You walk outside and fall in step with your fellow pilgrims, all of whom are headed to Santiago de Compostela, Spain.

Your only task for the day is to walk. You stop periodically for food, drink, and rest. You meet other...