Once upon a time, Dwayne “The Rock” Johnson was a sort-of normal person. His new athletic competition show, The Titan Games—premiering on NBC January 3 at 8 p.m. ET—reflects how he moved way, way up in the world while bulking up beyond most people’s dreams. “I think part of his motivation for doing the show is him thinking back on his life and how fortunate he’s been,” says Arthur Smith, an executive producer for Titan Games. “He wants to give back. So much of this show comes from his heart because of what he went through. It’s very consistent with what he does on social media—motivating people to be the hardest worker in the room. So many of these people are his followers he inspired.”In addition to Johnson’s role as a quasi-host/commissioner of the series (he was on set every day, and will be in all the episodes), the action star serves as an executive producer. The elaborate challenges are based on his own workouts and physical achievements, according to Smith. Contestants will face off against each other, ending on a mountain-like structure naturally called Mount Olympus—which Smith refers to it as “hell”—vying to become Titans. The series will crown…