While participating in THR's Writer Roundtable, Waititi revealed that the version of Hitler that he wrote and portrayed "shares nothing with the real guy other than the mustache."

"He is conjured from the mind of a 10-year-old, so he can only know what a 10-year-old knows," he said. "I had no interest in writing an authentic portrayal, or even when I played him, I had no interest in actually putting in the effort or putting in the research because I just didn't think he deserved it."

The writer added that he didn't want to give the real Hitler the "satisfaction" of Waititi doing research on him. "Screw this guy. I'm not gonna do that," he said.

"There's only one moment when I used some of one of his speeches from one of his rallies. This moment when he gets very serious and it's really Jojo's conscience kind of trying — this sort of dark side of his conscience trying desperately to hold onto him — and everything else I tried to write him as visions of myself in there and how I used to think of him when I was a kid and how children perceive the world," he explained. "All of that is kind of filtered through that character."

"I wanted to tell a story about kids witnessing the behavior of grown-ups — especially during times of conflict and war — because I've never seen films like that, I've never seen films where it was told really through a child's lens," the writer, director and star told THR at the film's Los Angeles premiere in October. "It became particularly important to me after becoming a father and realizing that children are constantly watching us, they're always looking to us for advice and for wisdom and for life lessons, and sometimes we fail them, but when we really fail them is in times of war. War is such a stupid thing and it makes no sense, and when children see us behaving this way, it only perpetuates the behavior."

Waititi also revealed that he was inspired to make Jojo Rabbit after reading a statistic that 41 percent of Americans and 66 percent of American millennials had never heard of Auschwitz. "That really struck me because I felt like at the end of the war they said, 'We should never let this happen again, we'll never forget,' and it's 2019 and kind of feels like we're starting to forget," he said. The filmmaker added that he hoped the movie would continue the conversation and keep memories of those lost in the Holocaust alive.