"People are like, 'She just can't handle' – for lack of a better word – 'the spotlight.' No, actually, I can't, and this is totally who I am," she admits in the March issue of Marie Claire.
"I don't try to force it or turn it into something else or fabricate this personality … so I totally agree when people say I'm, like, the most awkward person."
The 23-year-old, who got her start as a child but rocketed to fame in the Twilight films, says she "had no idea Twilight was going to be huge" – or that she would end up falling for her costar, Robert Pattinson.
"You don't know who you will fall in love with. You just don't. You don't control it," she says.
Tesh / Marie Claire
Stewart's relationship with Pattinson imploded in 2012 after she had a fling with Rupert Sanders, the married director of her film Snow White and the Huntsman.
While Stewart issued a public apology, and they reconciled, the couple seemingly split for good last year.
But for Stewart, who admits she lives a "fly-by-the-seat-of-your-pants lifestyle," there's no looking back.
"I stand by every mistake I've ever made," she says. "So judge away."