Besides inhaling handfuls of candy, carving pumpkins is the most symbolic aspect of Halloween. But as I was scooping out the slimy innards of my future jack-o-lantern -- pumpkin seeds stuck on my face -- I stopped and asked myself: What that hell am I doing? Think about it: a pumpkin isn't something that crosses our minds the other eleven months of the year. It isn't part of our regular diet, and then 'Weenie time come around and we go pumpkin crazy. We hollow it out, cut pieces to make it look like scary face and stick a candle in it? That's... weird!
So where does this tradition come from? Hundreds of years ago in Ireland, October 31 was a holiday called "Samhain" -- it marked the end of summer on the Celtic calendar. Samhain was a spiritual celebration that symbolized a beginning and an end, just like birth and death. It was believed that on this day the dead and living mixed; entering the bodies of the living was the one chance the recently deceased had of making it to the afterlife. (And if this is how reincarnation actually works...? SCARY.)
Of course, no druid in their right mind wanted some creepy spirit in them, so they'd dress up in scary costumes to spook the spirits. The other way to fend off these ghosts was to carve out turnips or gourds and place a burning lump of coal in them. People set them out on their windowsills or porches to frighten away the bad spirits.
When Europeans eventually settled in America, they discovered pumpkins were much easier to carve! (Thank goodness for that, have you guys seen gourds?) And lumps of coal were replaced by the more convenient candle.
So, there you go: Jack-o-Lanterns 101. They don't teach you this stuff in school!