In "The Normal Heart," actress Julia Roberts plays a wheelchair-bound doctor at the onset of the AIDS crisis in the early 1980s, and Roberts said the film has an important message.

"Moving forward, if something were to happen to us as a people, how do we take care of each other and how do we show compassion within fear?" said Roberts, 46, speaking of the message contained within the much-anticipated movie adaptation of Larry Kramer's largely autobiographical play.

WATCH: Julia Roberts, Sally Field Compete in 'Curse Off' on 'Jimmy Kimmel Live'

Roberts plays Dr. Emma Brookner, a character based on Dr. Linda Laubenstein, a New York doctor who treated AIDS victims. Roberts turned down the role of Brookner twice before signing on to join the cast that includes Mark Ruffalo, Taylor Kinney and Jim Parsons, among others.

"The first time I read it, I couldn't connect enough to my character," she told "Good Morning America" co-anchor George Stephanopoulos.

"A little bit of it is my own personal growth, I think, and really dismantling my character down to her as a person - because it's so much about her as this doctor and her as this crusader," the Oscar-winner said of why she changed her mind. "I did a lot of research on polio."

Once she connected to her character, there were other challenges. For one, the director of photography was Danny Moder, Roberts' own husband, which brought its own pressures.

"Because he's my husband, I want him to think I'm so cool," said Roberts, who has three children with Moder, her husband of nearly 12 years.

WATCH: Mark Ruffalo on Bringing 'The Normal Heart' to the Silver Screen

Roberts, who is known for her physical presence on the big screen, had to adapt to being in a wheelchair. She described it as having most of her "tool box taken away."

"My physical mobility was … just gone, I could only really use my arms," she said.

Julia Roberts Reveals Details of Her Most 'Idiotic' Tattoo

Now that the research and filming for the movie are behind her, Roberts can turn her attention t0 what she said are her two favorite hobbies.

"I guess my favorite hobby is knitting, or cooking," Roberts said in response to a Facebook question from an ABC News viewer.

When asked by that same viewer asked her to reveal, "mom to mom," what she was passionate about, Roberts replied: "I have this incredible teacher who has been teaching me more and more about nutrition."

Also not to be forgotten is the epic, and surprising, "Celebrity Curse Off" Roberts had recently with her "Steel Magnolias" co-star Sally Field.

WATCH: Jim Parsons on Playing a Gay Activist in 'The Normal Heart

The segment, from a recent episode of "Jimmy Kimmel Live," saw Roberts get trounced by her fellow Oscar winner and former "Flying Nun" star.

"Alright, let me just say, for the record, I could have blown her away," Roberts said playfully. "But I couldn't keep up because she came out just guns blazing."

"The Normal Heart" debuts on HBO on May 25.