Death at "Old Age"

Dad died at 80 and Mom died at 83. When people die around these ages I hear comments of comfort like "He lived a full life." This is meant to say we can't complain when we've been given 8 decades, as if 8 is enough (or 9 or 10). What does that mean, enough. Life is precious. Reality is that life is given for a moment and then is gone, but I refuse to put an "expectancy" on the length of life.