The instructor walked into the classroom where several students already were getting set to take notes and looked upon them expectantly.
"Today, we're going to speak of human history, as in how far was a human's instinct to survive and prepare. That is, the psychology of what humans, in that era, called Preppers, and how that psychology is ingrained in humans into the modern day. We'll explore the benefits, and the costs, of such a mindset, and how companions can better understand such mindsets in order to pack-bond with their humans." -- Lessons
Some ancient humans before the Shattering Era foresaw the end of the world as they knew it. It came, initially, as a mushroom cloud that laid waste to vast areas around it. Something about the image of a whole human being turned into nothing more than a shadow got straight to their instincts.
In the previous wars, everyone was expected to have a bomb shelter. A simple underground space in which to weather out the more common explosives. They were not built to be a shelter for more than a handful of hours.
Nuclear weapons rendered the land above the shelters unlivable for decades. Therefore the shelters had to be deeper, roomier, and filled with supplies that would also last for decades. The world above would be changed forever, they reasoned, so they needed to prepare.