Wayward forecasts have been part of the human condition since at least the Oracle at Delphi. People hunger for insight into the future; numerous methods of forecasting, from the statistical to the mystical, aim to satisfy that need.
The painful truth is that the only non-trivial predictions that can be made confidently lie in the natural sciences. In human society, there is no equivalent to Newton's laws of motion and gravity. Huge industries are devoted to forecasting economic and financial variables, with smaller ones predicting political change, technological trends and demographic shifts. Yet in all these disciplines, expert knowledge does not equate to forecast accuracy.
Economists are notoriously unable to predict turning points. There is no evidence that City gurus are able to predict the stock market, and some widely used techniques – such as extrapolating from past price changes – are no more scientific than alchemy. The return of the Cold War, the rise of China and the advent of the internet went unanticipated by visionaries. Malthusian predictions, popular in the 1970s, about the limits to growth proved bogus. Pointing to unfulfilled prognoses is not Schadenfreude, but a liberating message. History is not determined. It is governed by chance events, dumb luck and human ingenuity.