In the days of Cicero, there were complicated ways by which long speeches could be remembered by a complicated mnemonic process. I can't remember where I read about it, most likely in Scientific American. Maybe some of our Latin and Greek scholars can tell us about it.

A sample might be the orator enters a room, the door reminds him of his first paragraph, the table reminds him of the second, each item on the table reminds him of successive sentences or paragraphs.