In the decades since “Titanic” was released, Kate Winslet has proven herself as a Hollywood staple – something she once believed was only just a “fluke.”

The actress, 45, joined Michelle Pfeiffer, Rashida Jones, Vanessa Kirby and Andra Day for The Envelope’s Actress Roundtable and spilled on why she worried her success was pure “luck.”

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After Kirby asked, “Did it like blow your mind after it came out and you realized that that many people were watching you in the cinema?” She explained, “I didn’t. I was playing an American for the first time. And working with Leo [DiCaprio], who I’d seen in ‘[What’s Eating] Gilbert Grape’ and ‘Basketball Diaries.’ So it was like, ‘Oh, my God, I’m Kate from Reading.’ I was the overweight girl who would always be at the end of the line. And because my name was a W, sometimes I wouldn’t even get in the door of the audition because they’d run out of time before the Ws. And I was in ‘Titanic’. It’s mad.”

But even after the success of “Titanic”, Winslet admits she “was scared of Hollywood.”

“A big, scary place, where everyone had to be thin and look a certain way. And I knew that I did not look that way or feel like I fit there, so if I was ever going to belong, I had to earn my place,” Winslet said. “And to me, I hadn’t earned it.”

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“‘Titanic’ might have been a fluke. I had done ‘Heavenly Creatures’. I had done ‘Sense and Sensibility’, which I was nominated for an Academy Award for at the age of 19, but still, I had this feeling of ‘maybe that was just luck,'” she continued. “When I became a mother at 25, all of that stuff evaporated completely. Then two years after she was born, I was asked to do ‘Eternal Sunshine [of the Spotless Mind].’ I do believe that was a huge turning point in my career, because from then on people suddenly went, ‘Oh, she can do that?!'”

Winslet’s latest project, “Ammonite”, is generating Oscar buzz for the actress once again.

Winslet has been nominated for an Academy Award seven times and has won one statue for “The Reader” in 2009.