David Wong, writing at Cracked, offers an explanation for the real reason for the season:

It’s hard to understand why Christmas came to be a big deal even for people who have never stepped foot inside a church without understanding the context. And the context — which does predate Christianity by thousands of years — is that December kicks off winter in the Northern hemisphere. And for most of human history, winter meant a bunch of us were going to freaking die.

We’re so detached from that idea today, when the cold means nothing more than mild annoyance and sometimes slippery roads, that it’s hard to grasp how recent this was, and that this was the way of things for virtually all of human history. Every year, you headed into winter with just enough stored food and fuel to get by. The old and the sick knew they might not make it through, and an especially harsh winter could mean no one would feel the sun’s warmth ever again. Every year, you watched all of the plants turn brown and shrivel into husks, followed by an unrelenting darkness and cold that threatened to swallow you and everything you love.

And looking back at that, we see an awesome little portrait of exactly how much humans kick ass. Every year, you see, winter arrived with a short day followed by the longest night of the year (aka the winter solstice), and since before recorded history, humans have been celebrating that day with a feast, or festival, or outright debauchery. On that longest night before the frozen mini-apocalypse, in all times and places you would find light and song and dancing and food. Cattle would be slaughtered (to avoid having to feed all of them through the winter), families would travel to be together, and wine would flow. Precious supplies were dedicated to making decorations and gifts — frivolous things, good for nothing other than making each other happy.

These celebrations went by many names over the millennia, and everyone did it their own way. But deep down, I think the message was always the same: “We made it through another year, some of us won’t see spring, let’s spend a few days reminding each other of what’s good about humanity.”

One way of looking at it is that no one seems to celebrate winter in Westeros, although they offer oft-grudging appreciation for family.

He goes on to explain how this is still relevant today:

“Wait,” you might say, “so your inspirational, ‘true meaning of Christmas’ is that we should remember how our filthy ancestors used to freeze to death on a regular basis?” No, Christmas isn’t magical because of what it was, or where it came from. It’s magical because that’s what it still is.

See, around this time of year, my social media also fills with friends and acquaintances half-joking about having to tolerate the holidays around their extended family, people they only see once or twice a year with whom they have nothing in common and don’t like talking to. It all seems so arbitrary to them, a holiday that as a kid meant free toys and as an adult means travel, shopping, and trying to remember the name of your cousin’s new wife while the two of you make awkward conversation around the eggnog fountain. But that’s only because we’re separated from that ancient, unspoken truth, which is that this festive gathering around the fire might be the last time you see those faces.

And that part hasn’t changed.

Hug those weird family members, and try to remember what you love about them. It’s only for a day or two, and you’ll miss them when they’re gone.