This is no different from fortune telling (http://en.wikipedia.org/wiki/Forer_effect http://en.wikipedia.org/wiki/Forer_effect). Make a bunch of predictions, so

This is no different from fortune telling (http://en.wikipedia.org/wiki/Forer_effect http://en.wikipedia.org/wiki/Forer_effect). Make a bunch of predictions, some will be accurate, some will be a off, and some will be really bad. But people will remember the accurate ones and adapt enough the off ones that it looks like you were a visionary.