[throwaway60707]

Agreed on all being fantasy but

> All of humanities memories somehow encoded in DNA

Why not? The Dune universe is in a very far future, the books are happening 10 thousand years after humanity has been practically completely replaced by AIs and mind-uploaded humans for another 10 thousand years. The factions in Dune perform extensive bioengineering, and that is after the anti-computer revolution.

Why couldn't the computers/people with computers/people-computers before the revolution bioengineer the genetic memory? Or the people who performed the transition back to biological life, perhaps as a way to ensure nobody ever forgets the 10 thousand years of slavery?

> interstellar space travel from taking too many drugs

Interstellar travel in Dune is done using the Holtzmann effect, basically a warp technology. The spice gives them precognition abilities that are necessary to not crash into something while warping.