Emma Watson says that she learnt a lot about herself when she played Sam in Stephen Chbosky's latest movie The Perks of Being A Wallflower.
It's the first major film role for the British actress since she finished playing Hermione Granger in the Harry Potter franchise.
She explained: "I think I didn't realize how many restrictions I put on myself and how constricted I'd become, I think, as a result of playing that particular role (Hermione Granger) and then also there's so much scrutiny and so much attention on whatever I do.
"Playing Sam helped like free me up, liberate me, and make me a bit more spontaneous and it helped break down some barriers."
Adapted by director Stephen Chbosky from his own novel, The Perks of Being A Wallflower casts Logan Lerman as a deeply troubled high school freshman called Charlie. He falls in with a crowd of smart, nurturing seniors dealing with plenty of issues of their own.
Watson and We Need To Talk About Kevin star Ezra Miller (Patrick) are the step sister and brother duo who take Charlie under their wing as he embarks on a journey of discovery.
Watson's character is a long way away from her role in the Harry Potter films. "She's kind of like the opposite of Hermione," said the actress.
"She's like very loose and spontaneous and she loves to dance and she's kind of whacky, but then there's also this very like vulnerable, sweet, troubled side to her as well. She was a fun character to play, but it was also nerve-wracking for me."
- The Perks of Being A Wallflower will be released in the UK on October 3.