Georgie Henley was "bullied mercilessly" at school while filming the 'Narnia' trilogy.
The 22-year-old actress shot to fame when she was only eight as Lucy Pevensie in the Disney series but admitted it had a toll on her education because she "didn't have the confidence" to be proud of her work.
Speaking to The Times newspaper, Henley said: "I loved the work side of school, I loved learning, but the social side was a minefield.
"And part of that was worsened by the films that I had done, by me being in and out of school.
"There is such a pressure of child stars not to admit that it's hard. To smile and say 'yeah, I love my double life', and pretend they are a special agent or something.
"It was that thing of not wanting to put your head above the parapet for fear of it being sliced off, but I should have had the confidence to be proud of what I did.
"I was bullied mercilessly; people were so awful to me at school. It was amazing getting to uni and people being, like, 'That's so cool!'
"And I was, like 'I know, right?' So I wish I could say to the 13-year-old me, 'Be proud of what you've accomplished'.
"And that doesn't mean being arrogant. They are not the same. I think I conflated the two things."
After starring in the three 'Narnia' films - 'The Lion, The Witch and The Wardrobe', 'Prince Caspian' and 'Voyage of the Dawn Treader' - Henley has secured a number of other roles, but she is now looking for challenging projects.
She said: "Some child actors grow up and their career gets quite calculated. Their agents say, 'you can do an indie film, then you have got to do a blockbuster, and then you can do two more indies', but I'm just looking for stuff that scares me and challenges me.
"Because I still feel like I don't know anything and I have still got lots to learn, so having to jump in at the deep end like this..."