Keira Knightley says she joined Twitter -- then changed her mind.
The 28-year-old Oscar-nominated actress signed up for the social networking service under a false name after hearing friends rave about it and then quit after 12 hours, according to Harper's Bazaar UK, which features her on its February 2014 cover.
"It made me feel a little bit like being in a school playground and not being popular and standing on the sidelines kind of going, 'Argh,'" she said.
"I like being private," she added. "I haven't asked a lot of the actresses who I really admire, 'How do you do it?' because I don't want to know. Maybe I'm childish in that way; I just don't want to know about your life."
Knightley rose to fame playing Elizabeth Swann in the first three "Pirates of the Caribbean" films and later received an Oscar nomination for her role in the 2005 movie "Pride & Prejudice." She can be seen next in the action thriller "Jack Ryan: Shadow Recruit," which is set for release on Jan. 17, 2014.