The 23-year-old told Marie Claire that she had no idea the film franchise was going to be "huge" – nor that she would fall in love with her onscreen partner.
"You don’t know who you will fall in love with. You just don't," she said. "You don't control it.
"Some people have certain things, like, 'That's what I'm going for', and have a subjective version of that. I don't pressure myself… If you fall in love with someone, you want to own them – but really, why would you want that? You want them to be what you love. I'm much too young to even have an answer for that question."
Kristen and Robert's relationship famously imploded when the actress had a fling with Rupert Sanders, the married director of her film Snow White and the Huntsman.
She issued a public apology and the couple briefly reconciled, only to seemingly split for good last year.
But Kristen, who admits to living a "fly-by-the-seat-of-your-pants lifestyle", says there is no looking back.
"I stand by every mistake I've ever made," she said. "So judge away."
During the interview, Kristen also discussed the public's perception of her. "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 told the magazine.
"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."