In Advice to My Son, it seems as though the advice being given is coming from someone who has experienced war, "live your days as if each one may be your last (for they go fast, and young men lose their lives in strange and unimaginable ways) but at the same time, plan long range. It seems the advice he is giving is to plan for a long life, relish and enjoy your life but be aware that the end can come at any time and you must plan for that as well.