Two female, blonde carpenters, Anne and Caroline, were building a house. After spending a while on the roof, Anne noticed that Caroline would frown at almost every nail she pulled out of her bag, then throw it to the ground below. Finally, Annes' curiosity got the best of her. "Caroline, why are you throwing away so many nails?", she asked. Caroline replied, "It seems that almost every other nail I pull from the bag has the head on the wrong end! They're worthless!"
"You moron!", Anne said, "those are for the other side of the house!"