So often, the world seems like a jigsaw puzzle -- one where you've long ago lost the box.  You can see an edge piece here, a critical corner over there, but you don't have a good idea what picture the whole thing forms when assembled.  Worse, you may have the wrong idea, and you keep trying to force together pieces that don't fit.  

That's how it is with the story the Bush administration sold us on Iraq.  You can tell there's something wrong.  Many of the pieces clearly don't go together.

Then you snap in the last piece, and it all becomes clear.