For purposes of session 2 prep and PC backstories, I found it useful to create a generic Genealogy of Apocalypse World Inhabitants for my current campaign. This assists players and the MC in imagining details about the parents and grandparents of current campaign characters. YMMV of course because all campaigns are different, but this should give you a good start:
Your Grandparents (you probably never met them, but it's possible)
People who were of childbearing age when the Great Dying began - they lived through it directly; they saw their entire civilization, nearly everyone they'd ever known, wiped off the face of the Earth. They invented and mass-produced the medical gear used by Angels today; their desperate experiments and perverted ideas of technological progress led to developments like the Violation Glove and airborne biological weapons, in addition to Off-Grid Communities, Cryo Chambers and Survival Vaults. They experienced the cannibal militias, the toxic rain, the great famine, the freak weather, the constant struggle to obtain clean water, and the initial eddies of the world's psychic maelstrom... and some of them survived.
Your Parents
Their children, who came of childbearing age when the Great Dying had begun to level off. They remembered much of the above from their childhoods, but by the time they reached adulthood the population had been reduced by 90 percent, and Survival of the Fittest was the rule. These people lived in very different world from their parents. For one thing, they lacked any direct experience of the previous civilization, so they had no personal memories of Life Before the Fall, or a world without a psychic maelstrom in it. Their new ideas of "civilization" were nascent, random, and frequently brutal. Some of these people began to develop new techniques, new social systems, new ways of living, scrounging, bartering, cobbling together little experiments that were sometimes workable, setting up the first "hardholds", adapting to the harsh realities of life... and some of them survived.
Your Generation
Their children, most of whom are of childbearing age now. That's you. You remember much of the above from your childhood, and things haven't changed that much. If anything the major concepts of the game world have now become crystalized: The psychic maelstrom exists, hardholds exist, and the various character classes (and all their accoutrements) exist. Welcome to Apocalypse World.