Do not forget this, oh, my darling: It’s tonight’s TCM showing of the classic 1952 Western starring Gary Cooper as a man standing alone – a movie made at a time when its analogies were both obvious and powerful. Today, another reason to watch is to pay particular attention to Grace Kelly, who walked away from movie stardom to become a real-life princess. She did well by herself, inarguably, but I sometimes wonder what roles she may have played in the years since, and just how luminous a star she may have become, had she played in Hollywood’s sandbox for another few decades.