Williams felt sexy playing Monroe
Michelle Williams realised the "pleasure" which comes from male attention while playing Marilyn Monroe.
The actress portrays the screen icon in My Week with Marilyn, which is due out later this year. Monroe was known for her curvy frame, so Williams had to bulk up for the part, which was tough.
She found any extra weight only made her face bloat, so in the end she wore padding around her hips. That, coupled with the sexy "wiggle" she perfected, won her many male fans on set.
"The expectation to be beautiful always makes me feel ugly because I feel like I can't live up to it," she told the American edition of Vogue magazine.
"But I do remember one moment of being all suited up as Monroe and walking from my dressing room onto the soundstage practicing my wiggle.
"There were three or four men gathered around a truck, and I remember seeing that they were watching me - and for the very first time I glimpsed some idea of the pleasure I could take in that kind of attention; not their pleasure but my pleasure.
"And I thought, 'Oh, maybe Marilyn felt that when she walked down the beach.'"
Williams was desperate to land the role as soon as she read the script. The movie is about the difficult relationship Monroe and Sir Laurence Olivier shared while making The Prince and the Showgirl.
Williams knew portraying the star would be a tall order though, so initially tried to make herself hate the role. When that didn't work and she won the part she set about preparing.
"I'd go to bed every night with a stack of books next to me," she said.
"And I'd fall asleep to movies of her. It was like when you were a kid and you'd put a book under your pillow hoping you'd get it by osmosis."
The 31-year-old star is looking forward to seeing how the movie is received. While at one point in her life she would have been nervous, that's not the case now.
She has a five-year-old daughter Matilda, her child with late actor Heath Ledger. Losing him and being a single mother has made her strong and she's now looking to the future.
"I feel like something has changed for me, but it's a new change, so it's going to be hard for me to describe. Maybe it has something to do with turning 30. I don't feel as shy or nervous or self-conscious. I have more confidence that I can handle what life brings me. I don't feel scared to have an idea and express it. I feel giddy about it because it's a complete transformation. It's like I've found my voice," she explained.
"I'm not lonely, and I think that has a lot to do with what's on my bedside table rather than what's in my bed."