A degree of suffering is required to accomplish anything of worth in this world. Even our most basic necessities require work. Man must build shelter, he must gather food, he must find or make drinkable water. Unless he is blessed by fortune he must work.
His life is readily marked by woe. We know happiness because we have known misery. We recognize our blessings because we have seen the accursed. We build ourselves up in our youth only be to taken low in our old age. We construct our masterpiece only for time to tear it down again. We experience the miracle of birth but after all life is lived our bodies are destined to return to the dust.
Is man's very existence then nothing but vanity?
Indeed all things are temporary, but your words inspired the youth, your actions compelled those of another, your generosity encouraged the same, your virtues helped a brother in his time of trouble. Everything you do will alter our posterity for better or for worse. Therefore work and do good; become an inspiration for the lost in hopes for a better future. This is man's lot.