I soon spear a nice fat catfish, skin it with a sharp flake of waste chert, cook it over a fire I made from some dry wood and pine needles, and eat it. I might be so successful that I can feed a few other people as well. However, unless they help, it is still individual action at work. Soon people gather around this great humanitarian and form a camp. A small nexus of human activity has formed, seeded by my willingness to give away the fruits of my labor but otherwise involving no cooperation whatsoever.
Dark clouds roll in, a fierce wind arises, and the heavenly buckets tip.
Everyone heads for their shelters to ride out the storm. Then one man closest to the lake notices the water rising. He watches helplessly as his camp floods and he is left standing in knee deep water. His neighbor offers to share his lean-too and for a time all are happy again. But the rain continues to fall and the water continues to rise.