I spoke to a man who described to me the nomadic life of a particular people in eastern Africa. His team went in to help these nomads with their living conditions. So they built a building and dug a well, and started a school. The team left and came back at a later time to find the building, school and well abandoned. The season had changed and the nomads moved on to better pastures the same way they have always done and the permanent structures couldn’t go with them.