The Bible does not give all the specifics concerning the preflood era.
As it shouldn't being the writings were constrained upon one singular culture.
The thing that has to realized with these mythological stories is that they were carried over and retold and perhaps rewritten by scribes
over the centuries, but still retaining the same original intension as to bring relevance to worshiped gods.
Speaking or putting thoughts on tablets was no less a natural progression of God's purpose for mankind.
Interesting comment, I'm wondering what purpose did the god of the ancient Hebrews evoke in all the other writings
by other cultures who worshiped other gods than himself ?
Since there is much evidence to show that civilizations existed well before the chronological time frame established in the bible !