He doesn't know how to use the three seashells! *snicker*lRookiel said:Toilet paper.
I know we would all be fucked without it.
OT: I'm gonna go with fire. Learning to harness fire for cooking and heating increased not only life expectancy but survivability as well. Without fire, humans would have had to stay nomadic to escape the harsh winters of the time, making agriculture a pipe-dream without it as well.