This article deals with the two German dictatorships of the 20th Century and their memories. The difficult pasts indicated in the title are two: the memory of German Third Reich, which affected the Germans of the two states founded after the Nazi defeat of 1945; and the memory of the German Democratic Republic, which involved its former citizens after the implosion and the collapse of the Communist regime after 1989. The author compares the two dictatorships and their respective and differentiated collective memories, and their evolution through time. Collective memories are considered for their relevance in the way historical experiences are perceived by people, and therefore for the crucial role they have in history. The author concludes that, although our common identities, responsibilities and capabilities continue to be defined in national terms, research is increasingly shedding light on the transnational dimensions of our pasts: Europe is becoming a reality.