Brutally honest, Bernanke admitted that he had no clue what was actually causing the current fragility in the U.S. economic recovery. While the FOMC statement assigned blame outside of the U.S., pointing at Japan along with rising food and oil prices, Bernanke was put on the spot by a reporter who noted the inconsistency behind that explanation and a lowering of long term forecasts. Bernanke took the hit, admitting only some of the factors were temporary and that he didn’t know exactly what was causing the slowdown, but that it would persist. “Growth,” said Bernanke, “will return into 2012.”
That reminds me of the classic F. A. Hayek quote: "The curious task of economics is to demonstrate to men how little they really know about what they imagine they can design."