"How happy we were once!" is a novel written by the German writer Wilhelm Speyer. The book tells the story of love between two young people during the First World War. The author successfully combined historical events with the images of the main characters, revealing their feelings, hopes and disappointments. "How happy we were once!" is a tragic but extremely moving story that will leave the reader with deep thoughts about how important love is in the face of war and even in difficult times of general grief.