Boemerezh is a Breton word meaning more or less “wandering about” used to refer to when somebody has suddenly lost the memory of landmarks in his own fields as if he had gone through another side of reality. It is no madness, but a sudden and temporary disconnection from reality. What if modernity was first of all this: in every sense a loss of bearings? Used in the case of Brittany in the 1960s, the classical notion of shift is used here as an analytical operator in order to understand why certain major transformations tend to wipe out traces and how modernity blurs issues.