#TBT: Nick and Amanda Were 'All That'

Then: Nick Cannon and Amanda Bynes were part of a cast of teens and, in Amanda's case, pre-teens on the Nickelodeon sketch comedy "All That" in the late '90s. "#TBT This is why I could never be a tough guy rapper!" Cannon captioned an Instagram photo of the pair, then about ages 18 and 12, respectively, alongside co-star and current "Saturday Night Live" performer Kenan Thompson. "Lol #NickFamily @AmandaBynes happy you are doing better."

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Now: Cannon, 33, is the host of "America's Got Talent," an actor, and the husband of diva Mariah Carey, but he still has fond memories of his days on Nick. However, Bynes has struggled. After some bizarre behavior over the last few years, including legal woes and ridiculous tweets, the 27-year-old was forced into rehab for mental illness in July. She was released to her parents's care earlier this month and is continuing outpatient treatment. So far, she's been spotted at Disneyland and touring the campus of the Fashion Institute of Design & Merchandising. Cannon has publicly reached out to her, including back in August when he penned an open letter that referred to her as a "sister." "You're not alone," he wrote. "I'm here for you. I understand. I care and I appreciate you, because that's what family does and that's what family is for."

Maybe it's time for an "All That" reunion?