Michael J. Fox says 'Once Upon a Time in Hollywood' scene where Leonardo DiCaprio's character forgot his lines inspired him to retire from acting

• Michael J. Fox spoke about his decision to retire from acting in an interview with Empire Magazine. 
• He said a scene from "Once Upon a Time in Hollywood" helped him commit. 
• Fox, 61, announced that he would retire from acting in 2020 due to Parkinson's disease. 

Michael J. Fox said a harrowing scene from "Once Upon a Time in Hollywood" inspired him to retire from acting. 

Fox, 61, shared details in a recent interview with Empire Magazine, via Variety, in which he offered another glimpse into his life with Parkinson's disease. Fox was diagnosed in 1991 at the age of 29 but didn't tell his fans or the public for seven years. 

Fox told the outlet he recalled filming "The Good Fight" on CBS and having difficulty remembering his lines. Fox's struggles reminded him of a scene from Quentin Tarantino's 2019 film "Once Upon a Time in Hollywood," where Leonardo DiCaprio plays a Western aging star in 1969. 

"I thought of 'Once Upon A Time In Hollywood.' There's a scene where Leonardo DiCaprio's character can't remember his lines anymore. He goes back to his dressing room and he's screaming at himself in the mirror. Just freaking insane," Fox told Empire Magazine. "I had this moment where I was looking in the mirror and thought, 'I cannot remember it anymore.'"

Fox added that the realization didn't rattle him. Instead, he was calm and said to himself: "'Well, let's move on.' It was peaceful." 

Fox's comments come amid the debut of his new film, "Still," which hit Apple TV+ on Friday. The documentary examines Fox's life with Parkinson's disease, which the Parkinson's Foundation describes as a neurodegenerative disorder that predominantly affects the dopamine-producing neurons in the brain.

In the film, Fox said he would spend hours in his bathtub with his head below water because he felt he "needed to suffer" following his diagnosis. 

"I just wanted to keep my head below water. I needed to suffer. I needed to go as low as I could go," Fox said.

In an April interview with "CBS Sunday Morning," Fox admitted that living with Parkinson's disease is "getting tougher." 

"You don't die from Parkinson's. You die with Parkinson's," Fox said. "So I've been thinking about the mortality of it. I'm not gonna be 80."