Why was the Roman defeat in the Battle of Teutoburg Forest considered to be such an epic setback when many battles in the preceding centuries had seen more Roman casualties? Estimates of the Roman losses at Teutoburg Forest are in the range of 15,000-20,000, whereas battles such as Trebia and Cannae had seen far greater casualties. However, the Romans seemed to get over those earlier defeats whereas Teutoburg Forest supposedly haunted Augustus for years and is often held responsible for the fact that the Romans never again tried to conquer Germania. What explains this divergence? Was there some kind of fundamental shift in demographics that made it harder to recover from these kinds of losses?