As season four of The Walking Dead creeps towards its close, let’s take a moment to ponder: why do more than 19 million people watch a show about zombies each week? Why do you have to go back to 2008 to find a show that could beat The Walking Dead in the ratings? Compared to other super-powered monsters (like vampires) zombies are pretty pathetic. They can barely even climb stairs. Plus, they’re gross. Did Robert Kirkman, the creator of the original comic book series, dream of the phenomenon it would become?