The actor, 48, opened up about working with Williams in the 1989 film Dead Poets Society in a PEOPLE exclusive clip of his upcoming interview with Willie Geist on this week’s Sunday Today.

“I didn’t realize at the time what a tattoo that movie was on my heart,” Hawke said.

Geist, 43, asked Hawke what he learned from the late actor who passed away in August 2014.

“He gave me the first taste of what acting could be. When it goes really well, you disappear and you’re in service of a larger story,” the Training Day actor explained.

He continued, “I did a scene with Robin, he asked me to sound my barbaric yawp over the rooftops of the world. It was an amazing experience because the deeper into that scene I got, by the time the day was over I couldn’t remember what had happened.”

“It was the first taste of how positive and how beautiful performance could be,” he added. “It’s part of a collective imagination when something goes right like that it has reverberations that last a long time.”

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Dead Poets Society centers around an elite conservative all-boys boarding school where English teacher John Keating (Williams) inspires his students through his teaching of poetry.

The film won the BAFTA Award for best film, a César Award and received an Oscar nomination for Best Original Screenplay.

Sunday Today with Willie Geist airs Sunday, Nov. 18 at 8 am ET.