"I think most of my generation are not particularly focused on the royal family unless a big moment comes along," he said.
For George VI - Prince Albert or "Bertie" to his family - that big moment came in 1936. His brother, King Edward VIII stepped down from the throne to marry a twice-divorced woman, Wallis Simpson.
As Great Britain prepared for war, Albert prepared to reign - while fighting a more personal battle: Trying to overcome a debilitating stammer.
"You see him running into this problem - it's absolutely heart breaking," said Firth. "I choked up watching him. It's very moving because it's not just the struggle. It's the courage with which he deals with the struggle. He just does it. He gets on with it. He grows through the silence, which probably seems like an eternity.
"And then something in your heart swells when you see him get beyond it, and get another three or four words out, before he hits another one."
The king's wife sought the help of speech therapist Lionel Logue, played in the film by Geoffrey Rush ("Shine").
"You look at Geoffrey Rush's character and you think, 'That's the guy we wish we all had in our lives to turn to. He won't give up,'" said Firth. "If he reaches a barrier, he will find a stealthy way around it to open this man up."
But through his work with Lionel, the king slowly finds his inner strength at a time when his nation needed him the most.
"Bertie is fascinated, maybe a bit envious of Hitler's uncanny ability to communicate," said Couric, of a scene in which the king watches newsreel footage of the German Fuhrer.
"You know, I think it's significant that he doesn't understand what Hitler is saying," said Firth. "He's aware of the menace, but he's tuning in to the brilliance of delivery, [whereas] Here I am, I can't even get two words out in front of a microphone.
"And here's this man who is using it to the most devastating effect on Earth, on a global level."
Firth described George's inner thoughts as: "How do I stand a chance? What would it be like to have that ability?"
What helped him through was an unlikely friendship that taught King George how to be heard.
"This is about two very brave men: One who has no idea that he's brave, and the therapist who decides he's going to find every means possible to reach that damaged place," said Firth.
"People knew this man was facing his demons just by speaking to them. I think there was a sense that it cost him something. They found it valiant."
For more info:
"The King's Speech" (Official Website)