And in particular, I'm always curious -- how much of what we know of cuneiform is just because using clay tablets made examples more likely to survive to the present day? You can kind of imagine there being a soft temporal horizon for different kinds materials and artifacts -- far enough in the past, there are some kinds of things we should expect probably can't be discovered. If the people at Gobleki Tepe (or any other really old site) were writing by making marks on leaves or tree bark, we probably never know right?