The plot of my next novel: Mars had a thriving population, with two powerful factions. They eventually annialated each other with two massive H-Bombs. Two small resourceful groups, called the Neanders and the Umanoids escaped by rocket ships just before Mutual Destruction, settling on a strange blue planet. By design, all knowledge about the world that was believed to have led to this catastrophe was destroyed, replaced by the elders of the two groups by silly stories about the creation of the world, and how future beings should behave.