When George R.R. Martin first started screenwriting in the early 1990s, his then-agent recommended he read “Adventures in the Screen Trade” by William Goldman, in which one of Goldman’s central maxims is “Nobody knows anything.”

“My experience with ‘Game of Thrones’ just confirms that Goldman had it right: Nobody knows anything. Don’t let anyone tell you what’s produce-able, not produce-able,” said the “A Song of Ice and Fire” author on the “Maltin on Movies” podcast, co-hosted by film critic Leonard Maltin and his daughter, Jessie Maltin.

The episode was recorded at the historic Jean Cocteau Cinema in Santa Fe, New Mexico, which Martin owns. The theater, which he bought, remodeled and re-opened in 2013, has evolved into a culture hub, hosting stand-up comedy shows, author events and the occasional “Game of Thrones”-themed burlesque show. Martin said he is especially proud of the popcorn they serve, which is both organic and made by the Amish in Indiana.

He also revealed that, despite having multiple projects in the works including five shows in development at HBO (up to three of which are “Game of Thrones” spin-offs) and a video game, he doesn’t think he will ever enjoy the level of success of the HBO series.

“The scale of ‘Game of Thrones’s’ success has — reaching all over the world and invading the culture to [such an extent] — it’s not something anyone could ever anticipate, not something I expect to ever experience again,” said Martin.

Part of that reach includes the parents who have decided to name their children after their favorite characters, like dragon queen Daenerys Targaryan.

“Kindergarten teachers are going to hate me, with the “a” and the “y,” when all these little Daeneryses start hitting school,” Martin said, laughing, adding that he routinely gets pictures from pet owners of their similarly monikered dogs, cats and iguanas.

Both Martin and Maltin touched on their roots in the fandom world, compiling and writing “fanzines” and how the web has fundamentally changed how fans express themselves — and not for the better.

“The internet is toxic in a way that old fanzine culture and fandoms  — comics fans, science fiction fans — in those days, was not,” he said. “There were disagreements. There were feuds, but nothing like the madness that you see on the internet.”

It’s something Martin and showrunners D.B. Weiss and David Benioff know well. Following the “Game of Thrones” series finale in May, some viewers expressed their dissatisfaction by starting a Change.org petition demanding that HBO remake the show’s eighth and final season; to date, it has been signed over 1.6 million times. The series finale drew a staggering 19.3 million viewers.

And fans will get to air their grievances — or shower compliments — one last time, in real life: HBO announced that members of the cast, including Nikolaj Coster-Waldau and Maisie Williams, will gather for a panel in Hall H at San Diego Comic-Con on July 19.