Noting that her performance is, in fact, a tribute to Day, Zellweger said of the older actress, "She's representative of the era."
"She represents that genre of film-making and she's sort of the paradigm of the ingénue, of 'the girl,' of the movie star. I think she's great," added the actress who herself played bright-eyed sweethearts in "Jerry Maguire," "Nurse Betty" and "Bridget Jones's Diary."
An ode to the Rock Hudson-Doris Day films "Pillow Talk," "Lover Come Back" and "Bring Me No Flowers," "Down With Love" is the story of Barbara Novak, a smart, feminist advice columnist (Zellweger) who warns her fellow women against falling in love and encourages them instead to find fulfillment without giving away their hearts. Catcher Block, a womanizing journalist (Ewan McGregor,) sees Barbara as a challenge and sets off to win her heart and prove that her theories are ridiculous.
Asked if she has ever been swept off her feet by a Catcher-like character, the 34–year-old Texan exclaimed, "No!"
"I was friends with all the 'Catchers' growing up," she explained. "When they were in junior high. The 'Catchers' to be. I was on the soccer team with them. I was on the baseball team with them. I was on the playground tackle teams with them. We raced around the block. We built clubhouses together. We 'found' good lumber at construction sites to use on our tree-houses together. 'Look what I found!' Some contractor was probably very, very upset, and so now, I knew better. Because I was in the boys club, I knew what they were talking about in the field and I didn't want my name tossed around the field."
So, did she ever use any of her friends' techniques of seduction?
"No. No! No! No. Nooooo!" Zellweger insisted. "I can't do that. I'm very old fashioned and shy. It takes me awhile to get to know people and I just can't do that. Oh, no! I can't do that! I'm a serial monogamist. Oh, no. It's true! It's a fun idea to entertain in my head, but no, never!"
In addition to offering her the chance to temporarily play in a fun, stylized world, Zellweger said the film also gave her the opportunity to co-star with "Moulin Rouge" lead Ewan McGregor, an actor with whom she has wanted to work with for years.
"I like Ewan," Zellweger said. "Ewan and I have been friends or a long time, but I've been his fan for even longer. We were like school kids every day. Dumb. We would clap our hands like kids at recess. We laughed so much."
In addition to their friendship, Zellweger and McGregor's recent experiences in flashy musicals also helped them dive right into the beautiful, wonderful fake world where "Down With Love" was set.
"Everything was choreographed," Zellweger said. "The shared experiences in musicals made dance rehearsals less lengthy and, of course, we both have great love for it, so we enjoyed that very much."
Although "Down With Love" has been described by some as counter-programming for the summer's big-action movies —- it will be released this weekend against "The Matrix Reloaded" -- Zellweger said she doesn't think of her projects in terms of genre.
"I don't think about that, really, in terms of genres or what I see myself doing" she said. "It's more organic than that. It just kind of happens. They come along and I don't think of it in terms of its scope or in terms of how it will be classified or what the end results will be, but more about the project itself and what the experience is going to be. Who it's going to be with? What will I learn? How I can I grow? If it fits in my life."
So, why did she choose "Down With Love"?
"It fit in my life in a big way!" she said. "It made me laugh. I loved this script. It was so smart. I had to read it a few times because so man things you miss the first time, you catch the second time around. I love the play on words, the double entendres. It's quick. It's like a Cadillac. It doesn't stop and if you didn't notice it the first time, you have to get it the second time."
Despite her popularity with audiences, filmmakers and her peers, Zellweger said she still can't get over how much her life has changed in the last seven years.
"All the time I think: 'Do YOU believe your life? Can you BELIEVE your life?" she said. "Still every day! I have imposter syndrome. It still freaks me out when I'm at the store and someone goes, 'You are Renee Zellweger!' That is the weirdest thing to me. I'll never get used to it."
"Down With Love" opens Friday.