There was a little nugget at the end of Milgram's piece that was quite provocative. In analyzing the responses to the question "where in the city would you meet a stranger if the meeting place was unknown to both parties", he found a "consensus... that the inhabitants share an implicit, intuitive knowledge of the city that can be crystalized given the proper stimulus" (111). The Tour Eiffel was for obvious reasons at the top of that list, but other selections (is 8% of the choices a strong enough piece of data?) reveal a set of menhirs that areevoking a force on people even as they move at a distance from that monument (or street). For example, you might get a cell phone call, and describe your location to someone as six blocks from the Opera, or in another instance, say that you just crossed Blvd St. Germain 10 minutes ago. The person on the other line will create a familiar picture of where you are. We all create mental maps of the city to orient ourselves, but what is interesting is where those mental maps overlap, and form a "collective representation".
In a disaster situation, that overlap is very interesting--for example, where would you meet a loved one after an earthquake? You could end up with a bunch of people anxiously waiting around, say the downtown BART station, all unsure of a missing person's safety. In this way the structure of a mental map collapses to a few hot spots--the rest of the city may as well be forgotten, and you only care about where you will find someone you love. In a non-disaster situation, you may wish to find someone to love by heading out to a bar or another spot in the city where you think a person with similar desires will be waiting. Again the city collapses into a narrow field of wants and obstacles to those wants.
The city is nothing more than a shifting set of tropes. It is a pliable structure; in any given city, is it not easy to project your own fantasy upon it? Perhaps it is even easier in Paris because it is so well defined by its monuments. So many narratives can be written upon the fabric, and they would be recognizable too by someone even only familiar with the city by film or literature.