Mandy Moore has reacted to Diane Keaton's death, nearly 18 years after they played mother and daughter in Because I Said So. "They say don't meet your heros but I got to work with one of mine and even call her 'mom' for a few months. An honor of a lifetime," Moore, 41, wrote via Instagram on Saturday, October 11. "What an incandescent human Di is and was." She continued, "I am so sad she's gone for all the reasons but also because it felt like she'd be here forever, dazzling us with her talent and charm (and her style, c'mon)!!! One of the very best to ever do it.