A lot of the accomplishments of Ancient Technologies were lost during the Dark Ages. Skeletal remains of gladiators' skeletons prove that the Romans had very advanced medical practices for the times, including successful brain surgery. This can be seen in that the skulls actually showed healing after the injury and surgery. There are also the engineering accomplishments of the Romans, such as running water and a city-wide sewage system and the famed Roman baths. Much was also lost when the library at Alexandria burned, including many of the drawings for Archimedes inventions, including the possibility of some that we never learned about. A French engineer has also postulated that the ramps for the pyramids were internal, not external, to the structure. Then there's the Bagdad battery, as well as the image of what might be a giant lightbulb drawn on the walls of an Egyptian Temple. How much more was lost that we had to rediscover or reinvent later? And did the ancients come up with all of those ideas on their own, or did they have help? And will we ever know?