Why is the framing of looking back on your life from your deathbed seen as more valid than any other point in your life? Are there good arguments for its validity?
However, I think an argument is that experience and knowledge about your own life is at a maximum (absent degenerative diseases, etc) just as it ends, and therefore taking advice from the person you are on your deathbed is taking advice from someone who knows more than you about everything, and has precisely the same goals for you as you do.
See: Kundera, "The Unbearable Lightness of Being"