Most surviving cuneiform is that kind of thing. Various incidental items, though, like the complaint letters sent to Ea-Nasir [1], suggest that casual discourse

Most surviving cuneiform is that kind of thing. Various incidental items, though, like the complaint letters sent to Ea-Nasir [1], suggest that casual discourse was far from unknown and may just have usually been done with un-fired clay that wouldn't have lasted for long periods. [1]: https://en.wikipedia.org/wiki/Complaint_tablet_to_Ea-nasir https://en.wikipedia.org/wiki/Complaint_tablet_to_Ea-nasir