Keira Knightley admitted on the 'The Graham Norton Show' that she signed autographs and had pictures taken while pretending to be Britney Spears.
The 29-year-old star said that although she has very little in common with the 'Toxic' hitmaker, as she hates singing in public, but she was very excited so decided to play along with the fan, Contactmusic reported.
This has happened three times with the 'Pirates of the Caribbean' star and she has also been mistaken for other celebrities like Kate Winslet and Natalie Portman, she further added.