Before you put on that Angry Birds costume and exhaust yourself roving from door to door pandering for candy take a minute to reflect on the tradition in which you are taking part. Halloween is believed to have come from an ancient Celtic festival dating back some 2000 years. November 1 was the Celtic New Year and marked the end of summer to the Celts so thay celebrated on is eve by wearing costumes made of animal skins and dancing around bomfries. Over the next two millennia this primitive celebration grew to be candy fueled costume ball that we know today.