It's in memory of the Canadian Great Depression. There wasn't an economic hardship, they just had a shortage of sleds, the winter of 1896. They used cardboard boxes instead, and now they do the same, every December 26th. As is tradition.
Never forget Canada's third greatest tragedy.*
*Their second greatest tragedy was a maple syrup shortage in 1964, when all the maple trees went on strike. The strike finally ended in February of 1965, when the prime minister agreed to put a maple leaf on the previously nonexistent Canadian flag.** Their greatest tragedy, of course, was in May of 2011, when the Princess of Canada was kidnapped by tooth decay. Thankfully, three brave champions rescued her, defeating tooth decay forever.
**Part of this is true. Canada didn't have a flag until 1965.
This concludes Massacre's I Just Made This Up: Special Boxing Day Edition. Please join us next time, when we'll be discussing the Louisiana Purchase.