It's complicated. But there's a writeup on the network that goes over what people know and how they know it. Once you've got access, you can take a look.

[ He pays attention to the parts that could hurt him and not much else. It feels - distant, somehow. Like the war back in the day, he supposes. It's in the background, in the weave of the world around him, but he doesn't care to know the specifics of how it started or why. He only wants to protect his people. ]

It involves dreaming and - weird shit like that.