Rucks mentions that The Kid talks in his sleep, revealing his past.
The Kid never got to know his father. He spent his early life living with his mother, the parent he got his white hair from. After having a rough time in school, he decided to start working at the Rippling Walls, and send his pay back home to support his mother. One day, when his term at the Rippling Walls was done and he returned home, he found his mother dead and the money gone. He was forced to return to the work on the Rippling Walls, the only person in history to work two terms there. He was there when the Calamity happened.