ET spoke with the EGOT winner at the film's New York premiere on Monday.
The 89-year-old actress reflected on her days as Anita in the original 1961 film, while at the premiere of Steven Spielberg's new iteration at the Rose Theater, Jazz at Lincoln Center, in NYC on Monday. Moreno, looking stunning in a black sequin gown, shared that she "wasn't aware" that the new version was being released 60 years after the original.
"I wasn't aware of that. Really, how amazing. It's nothing but amazing tonight. That is what this night is about," Moreno, who was accompanied by grandson Justin, told ET's Nischelle Turner. "He is so excited to be here. Imagine, my grandson. My beautiful baby boy is here to see this."
Justin, on his end, noted that he's the "lucky man," adding that he wasn't blushing over his grandmother's kind word. "I'm used to it. She always steals the room and earned every second of it."
The original West Side Story film was released Oct. 18, 1961, with Moreno earning an Oscar and Golden Globe for her performance.
"After the movie came out and I won the Oscar and the Golden Globe, I couldn’t get a job! Isn’t that bizarre?" she shared. "I was offered lesser gang movies and I said, 'No, I'm not gonna do that. I didn't work."
Moreno, meanwhile, has a role in the film as Valentina. She also served as executive producer. Lauded by Spielberg, she expressed, "The reason I got credit for executive producer was that he was taking everything that he needed and I was there to help out. I have opinions and some are not always greeted with enthusiasm but that's what producers do. It's an amazing experience."
She also served as a mentor to the young stars, newcomer Rachel Zegler, Ariana DeBose and more leads.
"What was lovely, soon after I joined the cast… I used to see them trail in at lunch time and say, 'Can you tell me what happened when... Who said what?' I loved it. Felt like Mami," she expressed. "Just lovely! I loved that they were interested."
"I feel privileged to have been in the same generation as he. To be here, to hear them in person, as they were written. That is a huge privilege," she expressed. "I’m so glad he was able to attend our recording sessions when we were doing the movie."
West Side Story arrives in theaters on Dec. 10.