because, looking back on the days of my youth, my father laying on the creeper under the car and me sitting on the stool beside the tool box. . .and my realization that: "i said 18 millimeter not 13 millimeter you idiot!". . .doesn't have the same ring to it as "i said 9 16's not half-inch you idiot!"
yeah. . .that pretty much sums it up for me. . .