Germans have been living in a dream

The story is old and takes many forms. A fairy-tale version, recorded two centuries ago by the Brothers Grimm, tells of a certain Karl Katz, a goatherd in the Harz Mountains of central Germany. One night a straying goat leads Katz deep into a cave. Tempted by strange men, he drinks a potion and falls asleep. On waking he finds that not hours, but years have passed. The world around him has changed.