How storytelling is the secret behind "The Last of Us" success and newfound audience

In a post-apocalyptic world, a father's determination to save his teenage daughter is highlighted in the 2013 video game, "The Last of Us." The multi-layered storyline has been adapted into a new HBO show — resonating with a different audience. 

It's become HBO's second-most watched series premiere in more than a decade, something that Neil Druckmann, creator, writer, and executive producer of "The Last of Us," both the series and the game, finds still hard to believe. 

"I'm waiting for a piano to fall on me or something cause it just feels too good to be true," Druckmann said.