Awaken to the mystery of being here and enter the quiet immensity of your own presence. — John O’DonohueOn a visit to Mexico City over this past weekend, the reality of seven billion souls struck me as I stared down a long boulevard with a never-ending crowd of people strolling one way or the other. Walking around in one of the world's largest cities (population about 20 million) and watching variations on the theme of human was fascinating.