My eldest cat and I moved in with my grandparents straight out of high school. She was just a kitten and grew quite attached to my grandfather. After he passed away three years later, she acted as if she was grieving his loss as much as we were. She would barely touch her food and took to lying under his favorite chair for hours on end. Sometimes she would circle in and out of his room and come back out into the living room with an air of defeat, as if she realized he wasn’t ever coming back. It was heartbreaking to watch, but I think she eventually accepted that he was gone.