I want to tell you this story. Afraid you might get bored, I'm telling it in third person. She assembled the main characters of the puzzle, then the border, pushing hundred of pieces out of the way to situate the outline. Most of the blue pieces were in and since some of them fit into surprising spots, she only slightly worried about the one by the blue flask in the upper right corner. When the number of pieces left was less than 50, she arranged them according to shape. The puzzling went faster. An outline of a two inny/two outty puzzle piece appeared, and, much to her consternation, nothing in either of the two color categories fit. She looked under the table, around the baseboards, under the laptop and all around - nothing. She checked the vacume canister - nothing. Eliminating most probable causes left her with one. During the border asssembly, pieces seemd to fit where another piece actually fit. And voila! One pesky piece looked OK where it was, but it wasn't the right location. Once she took care of the error, the rest of the pieces flew into place and the picture completed.
Where is the blue flask that had her worried you ask? Forgotten. Two days later, while sweeping the kitchen, she came across a puzzle piece, surely not one of the 1000 pieces from the recently completed one. But yes, she turned it over, saw the blue and put it into the blank spot she missed.
