Perhaps Italo Calvino said it best in "Invisible Cities":
Travelers return from the city of Zirma with distinct memories: a blind black man shouting in the crowd, a lunatic teetering on a skyscraper's cornice, a girl walking with a puma on a leash. Actually many of the blind men who tap their canes on Zirma's cobblestones are black; in every skyscraper there is someone going mad; all lunatics spend hours on cornices; there is no puma that some girl does not raise, as a whim. The city is redundant: it repeats itself so that something will stick in the mind. I too am returning from Zirma: my memory includes dirigibles flying in all directions, at window level; streets of shops where tattoos are drawn on sailors' skin; underground trains crammed with obese women suffering from the humidity. My traveling companions, on the other hand, swear they saw only one dirigible howering among the city's spires, only one tattoo artist arranging needles and inks and pierced patterns on his bench, only one fat woman fanning herself on a train's platform. Memory is redundant: it repeats signs so that the city can begin to exist.