Bring up the book of Genesis and you’ll likely end up in a discussion about the Creation and the Fall, and maybe Noah’s ark. This must reflect the memories of readers who started the book and didn’t get far. Consider who the star actually is in each of its 50 chapters:
Obviously, the hero of Genesis is Abraham, whose tale is the focus of wholly 15 chapters. Second place is his great grandson Joseph, who dominates 13 chapters. Jacob is next, getting nine chapters. Noah–he of the ark–is in a distant fourth place, with only five chapters (and the last of those is really just a genealogy of his descendants).
To put it another way, the super-famous legend stories, those about Adam and Eve and about Noah, roughly comprise just 1/5 of the whole book. The other 4/5–everything from chapter 11 onward–focus on four generations of the patriarchal family: Abraham, Isaac, Jacob, and Joseph.
It’s almost like those famous early chapters, like most origin stories, are mostly obligatory background to lay a foundation for the more important material about the covenant stories that really shaped God’s people.