I recently re-read the Meno. It occurred to me that people back really didn't have a lot to do. They didn't have ipods or playstations. They just all got around and talked to each other.
About nothing really. That's where the notion of the abstract comes from - as opposed to the concrete. It comes from a place of nothing - something that does not exist in the real - physical - material world but exists only in the imagination of the imaginer. A form if you will.