Memento Mori
Notice the skull in Holbein’s The Ambassadors. Fear not. The wise suffer not craniphobia. Crania motivate reflection on death, and as Plato noted, such meditation is essential for life. What kind of life? An excellent human life.
Inter faeces et urinam nascimur.* We’re born in humble and humbling conditions. We live a relatively small set of years, operating with finite bodies which are eventually buried, burned, or otherwise destroyed. We are burying animals, buried buriers. Yet it matters how we mortals live, the moral and intellectual virtues we cultivate, the selves we individuated.
You might object that if it all ends in permanent death, nothing matters, and hence we don’t matter, nor does how we live. Yet we take ourselves and our lives to matter, and objectively so. Why should we accept such mattering? Why think so highly of ourselves?
Here’s one reason. Suppose there is life after death. One’s experience in that place will depend significantly on character cultivated now. We’re decomposing composers responsible for making the character we take to hereafter even as our bodies break down and perish. Character matters. So don’t store up treasures that rust and rot. Seek the higher life, which moth can’t devour, and thief can’t steal. (Cf. Mt. 6:19-21)
You might object further that an afterlife, though necessary, is not sufficient for human mattering. My response: yes, to guarantee objective meaning, we need more. We need something whose mattering is a matter of aseity.
* The Latin proverb is attributed to Augustine and to Bernard of Clairvaux, though it is difficult to confirm either attribution.