Brendan Fraser Explains Why Oscar-Winning The Whale Role Was His 'Most Emotionally Demanding' Yet

Brendan Fraser's The Whale character is the "most emotionally demanding" of any film he's ever taken on.

In a behind-the-scenes bonus feature from The Whale's new at-home release shared exclusively with PEOPLE, Fraser, 54, reflects on his role in the movie as Charlie, a grieving, reclusive English professor struggling with obesity while also trying to reconnect with his daughter (played by Sadie Sink).

"His emotional world is, for all of that sadness he carries, an intensely optimistic one at the same time, because he sees in his students the capacity to be the best that they can," Fraser says in the clip. "Charlie can see the good in others, but he can't see it in himself, sadly."

The Whale screenwriter Samuel D. Hunter adds that Fraser "from moment one had that bright light, that humanity, that faith," while filming the movie.

"Even in the darkest moments you still see the big heart of a human being at the center of it," Hunter says of Fraser's performance, which won him his first Oscar on Sunday night. (The film also won Best Makeup & Hairstyling.)

RELATED: Brendan Fraser Says He Nearly Died While Filming The Mummy: 'I Was Choked Out Accidentally'

Kevin Winter/Getty

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

Elsewhere in the clip, Fraser says Charlie "is the most emotionally demanding character I've ever seen on paper."

"To play him I knew it would take everything I've got," he says.

Director Darren Aronofsky says in the clip that it was apparent to him that Fraser "wanted a challenge" with the part, for which the actor also won a Screen Actors Guild Award and Critics Choice Award, among other nominations.

RELATED: See Brendan Fraser Transform Into His Character for The Whale in Behind-the-Scenes Video

Taylor Hill/WireImage

At the Palm Springs International Film Awards in January, Fraser told PEOPLE that the praise The Whale has received has been "gratifying" and "eye-opening."

"It has made me have a sense of accomplishment by way of seeing how this story is changing people's hearts and minds," he said at the time.

"That's gratifying, to say at least, and that kind of opportunity does not come along in this circus show of show business that we all play along with sometimes," Fraser said. "But when it does, and it's material that's handled with care and the project comports itself in a way that's interesting and important, I feel very fortunate and lucky to be a part of it."

The Whale is now available on Blu-ray, DVD and digital.