Oh no, clearly I can't use a ruler right! Is it because I'm blonde?
Women are not alone in doing bad measurements . I am old enough to remember when a woman's three-number measurements were deemed all important. The problem lay in the average man having no idea how breast measurement was taken; thus, it was inconceivable to the average male mind that the woman with 34-26-36 measurements could have far larger breasts than another woman with 36-28-40 measurements. Cup sizes were not considered.
I used to be active in Group-C car racing, not behind the steering wheel, but in the shop, where the car was built up. Most men could not understand either horsepower and torque or how they could be measured differently. Worse, the two measurements are not like height and weight, nice fixed numbers, as horsepower and torque produce curved plotlines. Exaggerations were common, as were too optimistic outlooks.
An engine that delivers 100 horsepower on an engine mount might only produce 70 horsepower at the wheels. Which figure is right? They both are, but you must not lose track of which you are talking about. Optimistic outlooks predicted that applying three motor enhancements, each producing a 3% increase in volumetric efficiency, to a 100 horsepower engine must increase the power to 109 horsepower. They won't. Why not? You cannot exceed 100% efficiency; if you do, you have a perpetual-motion machine on your hands. If the engine's volumetric efficiency starts at 96%, then it can only passively increase to 100%.
George Orwell was not the first to write that "2 + 2 = 5," as Hermann Goering predates Orwell, when he stated, "If the Führer wants it, two and two makes five!"
In 1779, Samuel Johnson said it best, "You may have a reason why two and two should make five, but they will still make but four."
But if your wife wants to believe that 2 + 2 = 8, do not try to disabuse her, for to do so would be sexist in the extreme—and not as sexually stimulating.