> 1. The body of all written works.
> 2. The collected creative writing of a nation, people, group or culture.
> 3. (usually preceded by the) All the papers, treatises etc. published in academic journals on a particular subject.
> 4. Written fiction of a high standard.
So it sounds like you're basically describing definition (1). I make this judgement because "this tastes good" is not creative or fictional writing, which are key points in definitions (2) and (4).
Probably not. If 90% of classical Greek dramatic literature is lost, we can safely assume at the very minimum at least that amount of literature contemporary to Gilgamesh is also lost. There are probably at least 9 other works written around the same time, a little before or after, that would compete with its title as "first." And it is also doubtful something as complex as Gilgamesh arouse out of the blue. There would have been a progression of literature increasing in complexity leading up to it, that is lost.
Thus Gilgamesh is the earliest high literature still in existence. But there definitely had to be earlier high literature, and no judgements can be made on whether that earlier lost contemporary high literature was any better or any worse than Gilgamesh.
Definitely not. Being first does not remotely imply existence. The first gospels have long deteriorated into dust, and the earliest versions are copies of copies of copies. Further, it is astronomically unlikely that the earliest version of Gilgamesh in existence is the original.
> We can theorize that there were some previous works, but Gilgamesh is the oldest we can actually read.
There are quite a large number of works that can be no longer be read.[1] This does not mean they're literature any less than works that can still be read.
That is fine, but my assumption is supported by the history of literature. We don't see anything as complex as Dostoyevski's Crime and Punishment or Twain's Huckleberry Finn in 1000BC.
> Complex oral tradition could have led directly to complex story-telling literature. All it would take is someone writing it down.
Are there any examples of "complex" oral tradition that stand in contrast to simpler oral traditions? Could we compare the early Christian oral tradition with, say, Hopi oral tradition to determine which is more or less complex? I don't think this makes a lot of sense, but I would entertain supporting argument.
1. https://en.wikipedia.org/wiki/Puranas 2. https://en.wikipedia.org/wiki/Ramayana 3. https://en.wikipedia.org/wiki/Mahabharata
A takeaway menu for example is not under definition 4 but if accompanied by other texts could be an example of the written works of our species.