Kit Harington had only recently graduated from drama school and starred in his first play when he was cast as Jon Snow in HBO's "Game of Thrones" at the age of 21.

The massively popular show gave the young actor's career a "stratospheric boost," but he also said that experiencing that level of fame was something of "a shock to the system."

In an appearance at the first official "Game of Thrones" fan convention this month the 35-year-old credited his friends for keeping him humble.

"I kept a really solid group of friends around me who took the piss out of me all the time," he said during a Q&A recorded for "The Official Game of Thrones Podcast". "That's really important.  They did not let my head get big. They did not let my feet get off the ground. They kept me solidly down there. And they still do." 

Harington said that he learned to stay away from internet comments and stopped reading what people wrote about him. He protected himself and his confidence by reminding himself that "Game of Thrones" was "just a TV show."

"You can think you're the center of the earth and the biggest thing since sliced bread, but you're just on a TV show," he said. "Let's not get too big for our boots here."

Despite the success, playing Jon Snow left Harington lost about what to do next.

"You look for that thing your whole career as an actor. You look for that one thing that just goes big or that you're known for," he said. "And if you have it in your twenties, you're left going 'oh, s–t, what do I do now?'"

It wasn't until a recent conversation with "Thrones" co-creator Dan Weiss that Harington said he started coming to peace with Jon Snow's role in his life.

"And then you go 'well, I don't have to look for the thing anymore,'" he said. "I can go and do what I want. I can go and explore and do strange, weird stuff. I think there's a real release to that." 

In his post "Game of Thrones" career, Harington has appeared in Amazon's "Modern Love" series, shown up in a Marvel movie and will soon star as Frankenstein in a biopic about author Mary Shelley.

But there's still room for Jon Snow to make a return in his life. The Hollywood Reporter reported earlier this year that the actor is in talks to pick up Longclaw once again in a sequel series for HBO.

"I think where we leave him at the end of the show ... we wanted some kind of little smile that things are okay," he said at the Q&A. "He's not okay."

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