Onetime child star Amanda Bynes, who gained fame on Nickelodeon, has retired from acting. "I don't love acting anymore so I've stopped doing it," the 24-year-old announced at 3am yesterday—on Twitter, of course. "If I don't love something anymore I stop doing it." If she's burned out, it's no surprise, notes E!: Bynes starred in two TV shows, All That and What I Like About You, while still in her teens.