Hannah Montana fans are getting ready to celebrate the show's 20th anniversary, but one familiar face will be absent: Emily Osment. The actress, who played Lilly Truscott, the best friend of Miley Cyrus' Miley Stewart in the show, shared the disappointing news in a Monday, March 23, Instagram video. "Montana, have you ever heard of the show Hannah Montana?" she asked her Georgie & Mandy's First Marriage costar Montana Jordan in the clip. Jordan responded that he'd "never heard of it," prompting Osment, 34, to explain that "tomorrow is the 20-year anniversary of the premiere.