6. We Won't Learn Everything About The White Walkers
What do we really know about the White Walkers? Well, they're icy cold but have absolutely zero chill. We've seen a teaser of their 'kingdom', a couple of snippets related to the hierarchy, and of course, the battle at Hardhome demonstrated their power to raise corpses from the dead. They can only be killed by dragonglass or valyrian steel (that we know of) and they really, really don't have a particular fondness for human life or happiness. Apart from that, they're a bunch of fairly sound dudes... So fans do know a bit about them though their origins, motivation, and lifestyle remains a mystery. You'd expect it all to be answered by the end, but don't be so sure. There will be so much we don't know about the White Walkers even after the show ends.