Our tendency is to drift through life. If life is a sea, too many of us are rudderless vessels, at the mercy of the prevailing winds of social suggestion. Death in its impending brings us up short: it forces us to confront the whole of one's life and the question of its meaning. Death is thus instrumentally good: it demands that we get serious. To face it is to puncture the illusion that one has all the time in the world.
You might be dead before nightfall. In what state would you like death to find you?
East and West, death has served as the muse of philosophy and of existential seriousness.
Gotama the Buddha: "Decay is inherent in all component things! Work out your salvation with diligence!" (said to be the Tathagata’s last words.)
Plato: "nothing which is subject to change...has any truth" (Phaedo St 83).