In the 10th century, Córdoba had streets lit at night and public baths. Chronicles from the period credit al-Ḥakam II's library with hundreds of thousands of volumes, in a Europe where most cities still lived in literal and intellectual darkness.
The city didn't fall for lack of knowledge. Its libraries stayed full for decades after political fragmentation began. What was missing was a power structure able to protect and pass that knowledge on to the next generations.
The same lesson repeats in other civilizations. Rome had engineering superior to empires that came centuries later. Baghdad had the House of Wisdom, one of the largest centers of translation and science in the ancient world. In every case, the collapse didn't come from a lack of ideas.
Today we carry more information in our pocket than Córdoba ever held in its libraries. The question those civilizations left us still has no clear answer: what good is more knowledge, without a foundation to sustain and pass it on?
Maybe history's most useful lesson lies less in the empires that grew fast, and more in the ones that knew how to last.