Sometimes a good mystery can be satisfying even without a solution, but when it comes to TV, fans tend to prefer their questions answered, and loose ends tied up. But not every TV show gets the time needed to tell the story the creators intended, since networks care more about ratings than leaving their fans scrambling from unresolved cliffhangers or random twists with no explanation.
The Walking Dead
The first season of the The Walking Dead had its cast of survivors looking for an explanation for the zombie outbreak, and possibly a cure. They eventually learned what readers of the comic already knew: the zombie infection is carried by every human, living or dead. In other words, no matter how a person dies, they're already a zombie just waiting to be born. Creator Robert Kirkman has no intention of explaining where the pathogen came from, but fans shouldn't bother even trying to explain how it works. Despite the show's attempts at using real science to describe the infection, bodies that can move without bloodflow or organs are already impossible. To make things worse, the comic series has implied zombie bodies decay like real flesh, which means nearly all should be liquid after a month or two, and skeletons after a year.
Game of Thrones
The Game of Thrones fantasy series deals mainly with the politics of noble men and women, but from the very start, it was the mysterious White Walkers who stole the show. The blue-eyed creatures have faded into legend by the time the series begins, having remained hidden for over 8,000 years, but the massive Wall built to keep them in the North shows they were once the greatest threat ever seen. The creatures may appear as frozen zombies in the TV series, but author George R. R. Martin describes the White Walkers, or "Others" differently: in the novels, they are beautiful beings who speak an ancient tongue, craft impossible weapons, and are nearly unstoppable in every way. In other words: TV audiences hoping to see their origins or motivations explained shouldn't hold their breath. No one is left alive who remembers, anyway.