prophets are a dime a dozen and it's a fine line between prophet and "guy in a padded room with a nice jacket that buckles in the back"

I don't honestly believe that the future is carved in stone but rather quite fluid and can only be predicted in very general terms. sort of like the multiple timelines thing in that the future is determined by the decisions we make and the paths we choose both as individuals as well as a culture.
Cayce, Nostradamus, Zaphod, that nutcase Crowley..all made educated (or in Crowley and Zaphods case, drug induced) predictions that are so generalized that they could apply to almost any period in history with a little creative interpretation. That's why the rapture goofballs are still waiting on the mountain top. Not that they don't all have something to contribute to ones personal development, but don't take any of them too seriously.