Agreed. Thebes is a weak example.
I do agree with the premise about the mindset.
The one that sits with me is reading things from Europe at the beginning of the 20th century. They thought they were at the pinnacle of Civilization. While the Napoleonic wars was about a century old, I think they had a very naive and arrogant believe that they transcended the barbarity of the past. Boy were they in for a rude awakening.
Athens would be a good example of a society that thought it was invincible and suffered for that, but Hanson has already written about the war between Athens and Sparta.