There is a passage in the Hagakure “In the Shadow of the Leaves” that a samurai should meditate on death daily:
Meditation on inevitable death should be performed daily. Every day when one’s body and mind are at peace, one should meditate upon being ripped apart by arrows, muskets, spears and swords, being carried away by surging waves, being thrown into the midst of a great fire, being struck by lightning, being shaken to death by a great earthquake, falling from thousand-foot cliffs, dying of disease or committing seppuku at the death of one’s master. And every day without fail one should consider himself as dead.
When I think about death I know that everything that exists is fleeting and temporary, like a mist, not just myself, but every aspect of the universe. All the works of man, all the bones of our ancestors, all the knowledge we have produced and compiled, but we still desire perpetuation and timelessness. Defeat of death is the defeat of time itself.
We move through time as if stepping from one crumbling stone to another. In a very real sense, all you have is the flow of each moment, although this is itself a form of timelessness. My memories of life live on in some fashion. That much is undeniable.