There won’t be a chance to go into this unless I can manage to ret-con it in as an edit for the final graphic novel, but basically none of the original Genie had a childhood. Earth needed soldiers fast, and couldn’t wait to raise them from scratch. Instead they made the Genie as adults, and implanted them with false memories of a childhood to give them a semblance of humanity. Given the incredible complexity of creating a brain with 20 years of false memories, it’s likely the government saved some money by giving them all exactly the same (or at least very similar) memories. Add that to the list of things that make Zeus and his generation stand apart from every other person on Earth (including the alien persons and his own wife and children).