I Know There Are Unexplainable Things

My grandfather had a kidney failure and was admitted to hospital for a dialysis. He stayed in hospital for a week. One day, he asked my grandmother to ask my family to come down and visit him at the hospital. Of course, we went there immediately as soon as my grandmother called us. I was surprised when I saw him. He was very happy despite being attached to a machine. He talked and laughed with us as though we are not in hospital. We left that day with a smile, in hopes that he might get better. But that night, my mother got a call from my grandmother, telling my grandfather died in sleep. A week after his funeral, my grandmother told my mother that the day before he asked us to come to hospital he saw his parents in his dream. They told him it was his time. I don't believe in supernatural but my grandfather knew he was dying.