Charlize Theron, 36: I Haven't Been Single in 17 Years

Charlize Theron isn't used to being alone.

"I've never been single," the actress, 36, reveals in the December issue of Vogue. "This is the first time in my life. From the time I was 19, I've been in relationships, literally gone from one to the other within a month."

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The South African beauty split with love of nine years Stuart Townsend in January 2010, just months before she began working on her new film, Young Adult. According to Theron, the breakup helped reinvigorate her acting career.

"I really, really missed it. Like around week three, I had this horrible, sappy moment where I got a little overwhelmed," Theron says of working on Young Adult. "It was just a really great f-cking experience."

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"I'd gotten out of a relationship, and I was in this really floaty place. My feet weren't touching the ground. I just kind of turned to [director Jason Reitman] and was like, 'I feel like me again.'"

Still, Theron says she was desperate to save her relationship with Townsend, 38. "It was sinking, and I had to give it a fight," she explains. "I really wanted to try and make it work. That was the priority. I wouldn't do it any different way."

Being single, Theron says, has "been good for me. I'm a creature who's really found her comfort zone in relationships."

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In the interview, the Oscar winner also praises Kristen Stewart, her costar in 2012's Snow White and the Huntsman.

"She just turned 21," Theron says. "She's a child. When I think about myself at 21, I had just done The Devil's Advocate, and Keanu Reeves had paparazzi following him and Al Pacino said this thing to me: 'If I knew that my life would be under this kind of scrutiny, I would have never become an actor.'" And I thought, 'Wow.' I couldn't comprehend it."

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"And Kristen is just living this to the max and still has a sense of humor about it. There's this really lovely quality about her that just doesn't give a f-ck," Theron tells Vogue. "A lot of people say they don't, but then they go home and cry and pop a Xanax. Kristen actually doesn't give a f-ck. That's what's so refreshing about her."

"I'm looking forward to killing her and taking her beauty," Theron says. "That's what happens, right?"