[restalis]

Actually, I would understand cave drawings better than cuneiform writing, so I disagree on the level of universality involved in each.

(edit) Just to give you a sample of each:

http://en.wikipedia.org/wiki/Cuneiform#mediaviewer/File:Cyru...

http://www.pellegrino.de/wp-content/uploads/2013/04/26-cave-...