Usually only those of us who have watched a loved one suffer feel that way. My mother died from metastic cancer, breast that moved to her spine then into a brain tumor. It affected her mobility and thought processes. The last month of her life was awful. She was gone long before she actually died. My only thoughts were keeping her out of pain.
My Mom just passed away 6 weeks after taking herself off her meds and virtually stopping all nourishment. During the whole time we prayed for her to be taken quickly. It was an agonizing 6 weeks to watch her. But looking back, 6 weeks did go by in the twinkling of an eye compared to her 95 years.