Here is the passage mentioned and here is a slightly more detailed description of the clay tablet in question, taken from an older thread. Now from my understanding, we can't be completely sure that Kushim was a concrete individual - and obviously we don't know anything about him other than his name - but it's nonetheless a fascinating thought that this is the earliest named person we know of.

So, assuming that Kushim really was an accountant in Uruk sometime between 3400 and 3000 BC, what can we infer about his life from archaeology and other written records? What would his work as a bookkeeper have looked like? As one of the few literate people, would he have been part of an elite? Would he have a nice house in the city? What would his family have looked like? What would his religious believes be? Would he frequently eat barley and drink beer, the foods mentioned on his tablets? Could he maybe even have been a woman?