The dowager would presumably not be amused. Maggie Smith, who plays the cantankerous elder Lady Grantham on "Downton Abbey" says she has never watched the series.

Smith made the confession to Steve Kroft of CBS's "60 Minutes." The segment will be broadcast on Sunday, February 17 to coincide with the final episode of Downton's Season 3, which airs on PBS later that evening.

The veteran actress said she's amazed by the popularity of the period drama and is proud of it, but has never "actually seen it." When Kroft asked, "Never?" she replied, "No, I haven't watched it."

Smith's excuse for not having seen the popular drama is she would only agonize over her own performance.

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"Because it's frustrating. I always see things I would do differently and think, 'Oh, why in the name of God did I do that?'" she said.

The 78-year-old actress has won two Oscars, three Emmys and a Tony award in her distinguished career. She has appeared in many memorable movies, including "The Prime of Miss Jean Brodie," the Harry Potter films and recently in "Quartet," directed by Dustin Hoffman.

"I don't feel any different to the way I felt before and I'm not quite sure what [being a star] means," Smith said, speaking of her heightened celebrity since taking on the role of Violet Crawley. "I am familiar to people now, which is what I was not before. That is entirely due to the television set."

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When asked about her reputation for being an on-set perfectionist, she puts it down to her age.

"You're trying to say that I am what everybody says…I'm scary and I understand totally," she said. "Old people are scary and I have to face it, I am old and I am scary and I am very sorry about it but I don't know what you do."

(Nick Briggs/Carnival Film & Television Limited 2011/PBS/AP Photo)