The helmet isn't mine, but I once had that bumper sticker. I came back to the office, after spending the day out in the field collecting samples of some critter or other, to find it glued to the wall of my cubicle. With alterations. My aren't-we-clever friends had taken a sharpie to it, changing the 4 to a 9 and scratching out the 5 altogether.
More accurate that way, they said.