Why is it hailstones are always the size of something else?
Because an American will say they are 2/9ths of a foot across,
and
the rest of the world will go W T F? How many centimetres is that?
And the American will go..."You and your nancy socialist metric [bleep]. Real men measure in strange fractions of an olde english measurement. We won the revolution dammit! But we kept their archaic measurement system."