From the New York Review of Books: Manhood for Amateurs.
Most great stories of adventure, from The Hobbit to Seven Pillars of Wisdom, come furnished with a map. That’s because every story of adventure is in part the story of a landscape, of the interrelationship between human beings (or Hobbits, as the case may be) and topography. Every adventure story is conceivable only with reference to the particular set of geographical features that in each case sets the course, literally, of the tale. But I think there is another, deeper reason for the reliable presence of maps in the pages, or on the endpapers, of an adventure story, whether that story is imaginatively or factually true. We have this idea of armchair traveling, of the reader who seeks in the pages of a ripping yarn or a memoir of polar exploration the kind of heroism and danger, in unknown, half-legendary lands, that he or she could never hope to find in life.
This is a mistaken notion, in my view. People read stories of adventure-and write them-because they have themselves been adventurers. Childhood is, or has been, or ought to be, the great original adventure, a tale of privation, courage, constant vigilance, danger, and sometimes calamity. For the most part the young adventurer sets forth equipped only with the fragmentary map-marked here there be tygers and mean kid with air rifle-that he or she has been able to construct out of a patchwork of personal misfortune, bedtime reading, and the accumulated local lore of the neighborhood children.