I think there is a philosophical angle to this. I mean, my world map was constructed by chance interactions with the real world. Does this mean that the my world map is a close to the real world map, as their NN's map is to Manhattan? Is my world map full of non-existent streets, exits that are at the wrong place, etc. The NN map of Manhattan works almost 100% correctly when used for normal navigation but breaks apart badly when it has to plan a detour. How brittle is my world map?