invisible cities by calvino

"Marco Polo imagined answering (or Kublai Khan imagined his answer) that the more one was lost in unfamiliar quarters of distant cities, the more one understood the other cities he had crossed to arrive there; and he retraced the stages of his journeys, and he came to know the port from which he had set sail, and the familiar places of his youth, and the surroundings of home, and a little square of Venice where he gamboled as a child.
At this point Kublai Khan interrupted him or imagined interrupting him, or Marco Polo imagined himself interrupted, with a question such as: "You advance always with your head turned back?" or "Is what you see always behind you?" or rather, "Does your journey take place only in the past?"
All this so that Marco Polo could explain or imagine explaining or be imagined explaining or succeed finally in explaining to himself that what he sought was always someting lying ahead, and even if it was a matter of the past it was a past that changed gradually as he advanced on his journey, because the traveler's past changes according to the route he has followed: not the immediate past, that is, to which each day that goes by adds a day, but the more remote past. Arriving at each new city, the traveler finds again a past of his that he did not know he had: the foreignness of what you no longer are or no longer possess lies in wait for you in foreign, unpossessed places. (...) Elsewhere is a negative mirror. The traveler recognizes the little that is his, discovering the much he has not had and will never have."