Yes, the metaphor is an extended one and meant to be taken personally by the reader - all too often we limit ourselves, particularly re ageism - unwilling to take some risks, go a different way, or start over because we feel we're at a certain stage of life. Personally, I feel we all start each day on an equal footing with 24 hrs ahead and even that uncertain. As I used to say to my students, middle aged gives the wrong impression - that your life is half-over. There are no guarantees that any of us will even last through the day (and this, before school shootings!) so carpe diem - seize the moment :)