An African tribe called the Ik throws their children out of their homes once they turn 3. They are left to fend for themselves with no help from their parents at all, and to survive, form groups with others their age. These groups only last a few years, and every so often the individual will join a completely different group.
"Many strange things may be seen in the Great Swamps, not all real. But I tell you, there was a ship and it was real! Well it was old and all sails torn and had many holes in the hull... but anyway it was hundreds of miles from the Sea! How it came to be there, I can only wonder..."
(If it is not a hallucination, may be inhabited by wererats.)