No one is exempt from criticism.

Just ask Sir Ian McKellen, who stripped down for a 1974 rendition of “King Lear” in Brooklyn, only to receive a mixed review from John Simon of New York Magazine.

“When I got naked, he actually reviewed my private parts,” McKellen chuckles during a Zoom interview. “He praised my anatomy but thought my performance left much to be desired.”

Fast forward fifty years, and the esteemed British actor is stepping into the role of critic himself in “The Critic” (hitting theaters this Friday), where he portrays a sharp-witted reviewer named Jimmy Erskine. Set in 1930s London, this fictional tale explores the tense relationship between Jimmy and theater actress Nina Land (played by Gemma Arterton), who is frequently on the receiving end of his harsh critiques. She begrudgingly agrees to assist him in saving his job from angry newspaper executives upset by his biting reviews.

At 85, McKellen has maintained a balanced perspective on criticism. He participated in nearly two dozen college productions while studying English literature at Cambridge University, and he reminisces about one particularly positive review from that era, which labeled him “a name to remember.”

“That day, I resolved to pursue acting professionally, thinking I might just be good enough,” McKellen reflects. “And I’ve never regretted that decision.”

However, not all critiques have been kind. He recalls a 1971 performance of “Hamlet,” where the Sunday Times remarked that the “highlight” was “the curtain call.” Nevertheless, he has learned to brush off less favorable reviews.

“I try not to fixate on poor reviews,” McKellen states. “I still read them, but I stopped letting them bother me long ago. I see critics as being as trustworthy as a friend recommending a show.”

Ian McKellen views ‘The Lord of the Rings’ as his ‘Casablanca’

Throughout his remarkable career spanning over six decades, McKellen has taken on roles as formidable mutants (“X-Men”), seasoned detectives (“Mr. Holmes”), and even enchanted household objects (“Beauty and the Beast”). He has scored five Emmy nominations, along with wins at the Golden Globe and Screen Actors Guild awards. Despite this, he shies away from flattery.

“I believe I’ve received too much praise,” McKellen asserts. “If you’re performing a lead role in a Shakespeare play and you articulate the lines well, you likely don’t need to do anything more.”

His first Academy Award nomination came in 1999 for the poignant “Gods and Monsters,” in which he portrayed the gay director of “Frankenstein,” James Whale. McKellen, who identifies as gay, describes this role as the highlight of his career.

“It was an extraordinary character exploration,” McKellen says. “Looking back at videos from my early theatrical performances, I’m not particularly impressed. It reassures me that I’ve improved over time as an actor. Some of my work is worthy of being appreciated long after I’m gone.”

This includes his work in “The Lord of the Rings” trilogy, which earned him a second Oscar nomination in 2002 for his portrayal of Gandalf, the wise and selfless wizard.

“It’s been an incredible and unforeseen pleasure in my career to be part of a film that has achieved classic status — it’s my ‘Casablanca,’” McKellen remarks. “This allows me to attend events globally where someone always wants to engage with me because they’re fond of those films.”

McKellen takes pride in having his own memorable line: “You shall not pass,” which Gandalf famously utters in “The Fellowship of the Ring” while confronting the menacing Balrog. He recalls filming that pivotal scene with director Peter Jackson and a yellow tennis ball that would ultimately be transformed through special effects.

“I asked Peter, ‘I have the staff, the sword, and a tennis ball in my sightline. What does the Balrog look like?’” McKellen reminisces. “He replied, ‘We don’t know yet – we’re going to create everything on a computer.’ Consequently, there was one take where I directed my line at the tennis ball: ‘You! Shall not! Bounce!’”

“I couldn’t grasp much of the movie when I was acting in it,” he mentions. “I was unsure how it would all piece together, but Peter had a clear vision, my goodness.”

‘The Critic’ star admits it’s ‘difficult’ to come to terms with ‘not being immortal’

Based in London, McKellen has focused mostly on theater in recent times. He feels especially proud of his latest interpretation of “Hamlet,” which has been adapted into film. Anand Tucker, the director of “The Critic,” expresses admiration for McKellen’s vitality.

“I’m truly inspired by how vibrant he is at 85,” Tucker remarks. “His eagerness for life, openness to learning, and constant desire to experience new things is remarkable. There’s an infectious joy about him that’s refreshing.”

However, in June, McKellen faced a setback after he fell off stage during the West End play “Player Kings,” resulting in a chipped vertebra and a fractured wrist. This mishap forced him to step away from the production, which left him feeling “guilty and ashamed.”

“Inside, I feel 12, yet I also feel 85,” McKellen reflects. “People stumble daily without realizing it until they are in their 60s. But at my age, they must be cautious because a small trip could lead to a broken hip, and that’s something to avoid.”

He shares that he is recovering now, but has decided not to take on any work until next year, when he is set to have projects lined up. “It’s tough to come to grips with not being immortal – we all harbor a belief that we’ll live forever, right? Yet, if my friends aren’t passing away, they are often limping or combating health issues. I consider myself incredibly fortunate.”

In his spare time, the actor enjoys classical music and recently attended concerts by Barry Manilow and Elton John. He is looking forward to returning to New York: The last Broadway show he experienced was Bette Midler’s “Hello, Dolly!” in 2017 (“I was seated so close to the stage that I could feel the breeze from her skirt”). He also craves a slice of Junior’s cheesecake (“The most delicious thing to emerge from Brooklyn – I can almost taste it now”).

Ultimately, “I hope to return to Broadway one last time before I retire,” McKellen expresses wistfully. “It would be lovely to come back and say farewell.”