Los Angeles: Actress Emma Watson says she used to mess up lines a lot while filming "Harry Potter".
The 26-year-old starred as Hermione Granger in the popular fantasy film franchise.
She says she used to feel guilty for making the director redo parts of the movie, reports dailymail.co.uk.
Watson felt shy when she appeared on "Jimmy Kimmel Live!" and the host aired an outtake from the first film, "Harry Potter And The Philosopher's Stone", which saw her mouthing along to co-star Rupert Grint's lines.
"You're helping them with their lines," Kimmel joked.
Watson said: "You laugh, but this was quite traumatic for me because I created issues because of this! I would ruin takes! I would be like, 'I'm so sorry! I feel so bad!' I couldn't help myself."
She later explained that she was such a big fan of J.K. Rowling's series that she couldn't help uttering the words from memory.
"I was such a loser, I really loved those books, I really wanted to do my job well, and I kind of overdid it," she said.