Melissa McCarthy gets "psychotically attached" to her movie roles.
The Ghostbusters actress feels it is important to relate to her characters but admits she gets so involved with how they would think or feel, she ends up "annoying" her directors.
She told America's ELLE magazine: "I get so psychotically attached to all of my characters, and I fight for them in probably the most annoying way. I hear myself saying, 'She wouldn't phrase it that way.'
"I know it's such an actory thing, but I feel it to my core: I have to represent the woman I'm getting to be. Even if she's fictitious, she's always real to me: three-dimensional, flawed, loving, screwed-up, as real women are."
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ELLE are publishing four separate covers featuring the Ghostbusters cast and in her accompanying interview, Kristen Wiig recalled how she worried she would "pass out" during her Saturday Night Live debut.
Speaking to Will Ferrell, Kristen said: "My very first show I got on something that I wrote. I was weirdly less nervous for that than I was for the first sketch I was in, which was about someone being pregnant in their butt. I think it was [Amy] Poehler, and we had a baby shower for her...
"I was scared that I was going to freeze or swear or pass out."
Meanwhile, Leslie admitted she always expected her humour would help her career - but she didn't expect things to get so big.
She said: "I just knew that I was funny, and I knew that it was just a matter of time. I didn't know what was going to actually happen - this is definitely way bigger than I thought - but I knew there was no way I was going to be that funny and nobody was going to notice it."
And Kate McKinnon has grown to accept her impersonations are just a part of her and she really is Justin Bieber.
She said: "I came to a reckoning that [pretending to be other people] is in fact such a real, huge chunk of the way I communicate. I thought it was something I was putting on to disguise something else, but it's not."
Asked if that means she is Justin Bieber in real life, she said: "That is what I am telling you, yes."
- Bang! Showbiz