At the start of Still, two people—long ago, a couple; now, well over 60—are getting reacquainted in a swank hotel bar with a cocktail and a conundrum. Helen (Melissa Gilbert) comments that “the cells in your body” are “renewing themselves all the time,” and “after seven years you’re a completely different person,” at least “on a cellular level.” Mark (Mark Moses) recalls a “brain teaser” about a ship: “it’s made of wood, and every time part of it breaks they replace it with a part made of metal. And eventually every single part has been replaced. Is it still the same ship?”