Humans demonstrate not only an extraordinary capacity for transferring knowledge from one generation to the next, they are also supremely skilled in building on this know-how to create novel technology, whether it be an Acheulean hand ax or the modern electrical grid. This vast web of interconnected knowledge and practical capability has required the labors of millions over the millennia. The subtleties of technologies from stone flaking to high-voltage transmission lines could take a substantial time to recover if humanity were ever forced to reboot civilization after a nuclear conflagration, an asteroid strike or some other global catastrophe.