The REAL Holiday! 
For a start, there is no evidence that Christ was born at Christmas. Shepherds would not have had their flocks out in the fields in midwinter, even in Palestine. Nor would the Romans have ordered a census in the winter, the most difficult time of the year for travel.
As for the 12 days of Christmas, that's traditionally the time it took for the three wise men to arrive at the stable in Bethlehem. The fact is that the Roman celebrations around the winter solstice (December 21st), starting with the feast of Saturnalia and ending with the Sol Invictus festival, also lasted 12 days. All over the world, the solstice is connected with rebirth, so it made sense for the early Christians to tag on their own ersatz birth-celebration to one that was already around.
Or take Santa Claus. "Santa Claus" is "Saint Nicholas" mispronounced, and Saint Nick is the patron saint of children-as well as merchants and pawnbrokers, which seem rather apt. So how did Saint Nick, who lived in Turkey, end up at the North Pole, driving a sleigh full of reindeer?
It's claimed that part of the story goes back to the Norse god Odin, who also gave cash to the poor, and who used to ride across the sky. And there's Cernunnos, the Horned God who led the Wild Hunt, chasing souls through the night sky. Or Freya, another Norse deity, who was supposed to spend the twelve days after the winter solstice driving a chariot pulled by stags, giving presents to the good and punishing the ...well, the naughty. Whichever of the ancient legends you choose, one thing's for sure: Father Christmas is as Pagan as they come!

But red and white is also the colour of the fly agaric mushroom, a powerful hallucinogen from northern Europe, where it's a favourite food of reindeer. It used to be a big part of pre-Christian shamanic rituals, and is said to have formed from the specks of blood and spittle that fell from the mouth of Odin's horse as he galloped on (ta daaaa!) the winter solstice! And Christmas poet Clement Moore was an expert on European folklore. That's no coincidence.
Christmas was never a celebration of Christ's birth - there's nothing in the Bible to say that Christ's birth should be celebrated at all, and it wasn't until 375 AD that the Church fixed it's date. Instead, it was a way of twisting old beliefs to Christianity's advantage, making more converts for what was then the new faith on the block. Roman historians realised this: in 230 AD Tertullian wondered why the Christians were so willing to dilute their beliefs with Pagan "superstitions".
HOLLY: Supposedly something to do with Christ's crown of thorns, but in fact a lot more to do with the god Saturn and the old Pagan Holly King.
CHRISTMAS TREES: Evergreen trees were a potent symbol of life in the dark winter days. Decorating them was a way of making offerings to the tree's spirit.
PRESENTS: From the Roman feast of Saturnalia, integrated into Xmas in 375 AD when the church first set Christ's birthday as December 25th.
YULE LOGS: A Scandanavian tradition, where an oak log was kept burning for 12 days, and a piece of it saved to light the next year's log. "Yule" is named after Ullr, the Norse god of winter.
BOOZE: the old Greeks celebrated the death and rebirth of Dionysus, the god of wine and wild revelry, for 12 days at the winter solstice. Dionysus's parents were Zeus and Hera. When he was killed by the Titans, he was brought back to life and ascended to Mount Olympus.