I'm not talking from a sociological perspective, I'm coming from a systems point of view. History is of little use in predicting our future because things have speeded up so much. The flow of history is no longer laminar, it is turbulent, chaotic. When the source of all energy was wind, water and muscle and all food came from "a man walking behind an ox", empires could rise and fall and 99% of all people had the personal skills and resources to carry on. To someone who lived in say, 4th century Poland, it mattered little that the Vandals were sacking Rome. Even to the Romans, life would more or less resume after the Vandals left. The present is not just an extension of the past, it is something fundamentally different. We now live in an age when the system, the infrastructure we have constructed around us, is irreplaceable and is studded with bottlenecks, any one of which can bring the whole thing to a sudden stop if it fails. The system is adaptable and resilient to a certain degree, as countries at war demonstrated 60 years ago, when enormous damage and dislocation could be absorbed before everything just seized up. But sooner or later it will seize up. And we can't just drop back a century or two and start over. Next time, we go all the way back to the stone age.

A few years ago, when I lived in Silicon Valley, I was having this same conversation with some of my colleagues, and we decided we all needed a "nineteenth century skill" since it was obvious that maintaining applications software wasn't going to be a very useful profession after the Apocalypse. I was a sailor, another fellow knew how to keep horses and tack, a third was skilled at maintaining and repairing light machinery. When we asked our fourth companion what her 19th century skill was, she thought about it for a while and said "Golf."