Dev Patel "very often" suffers from imposter syndrome.
The 31-year-old actor identified with Gawain, his character in 'The Green Knight', because he thinks the tale of King Arthur's nephew is similar to his own journey as an actor, including having many moments of self-doubt.
He said: "Even though it's a medieval film, there are a lot of parallels for me with a young actor's journey through their career.
"The idea of being known and having ambition, but at what cost? And the idea that Gawain is surrounded at the round table by all these legends and not feeling worthy himself. I very often found myself in that situation where I have this impostor syndrome, just like him."
But although Dev identified with his character, the former 'Skins' actor enjoyed playing someone so different to many of his other roles.
He said:""For this film I got stripped of all that wide-eyed and open vulnerability stuff that I normally lean into. I got to play someone who becomes cold and callous and broken and jaded along the way."
Dev also reflected on the "crazy" time in his life when he was propelled to global fame thanks to his role in 'Slumdog Millionaire'.
He told The Times newspaper's Saturday Review: "That really was like being a lobster thrown into a boiling pot. It was ridiculous in every sense. I was plucked from my box room in Rayners Lane [in north west London].
"I was travelling everywhere by train and then suddenly I'm on the front page of the paper, and there's that moment in the carriage where every head, one by one, like meerkats, begins to turn and stare. It was a crazy experience. And I still feel like that today, in some ways. You can't take that Rayners Lane kid out of me."