Billions of people have been born in this world, and most of those billions of people have died and been promptly forgotten, eaten by maggots and washed away by the shifting sands of time. Whatever mighty things they did no one remembers because their peers are, like them, wiped away from the desert sands of earth's history.
But who are we! Even with that knowledge, we try (or do) our best to be remembered. We build stuff, conquer people, write stuff like "Brayo was here" on a filthy latrine wall next to big green houseflies and abstract art finger-painted using human shit, combine some or all of the above together among other things. Does it work? Maybe. We will not be here in three hundred years to see if those mabati structures in which we spent many a smelly afternoon pondering the chances of someone passing by and spotting our rusty phalli hanging from beneath the rusted-out bottoms of the latrine doors while we attempted to wash the floors with our liquid diarrhoea still stand. And if they do stand, will we care to go back and see? Will we even remember?
Sometimes, our impact is much less subtle but longer-lasting than we expect, like the alphabetical characters some Greek genius(es) developed and Romans copied, or the numerals the Arabs developed that actually for once make sense. Sometimes it is in the little moments in which we consent to various beliefs, actions and ideas, creating this little soup we call "culture" and sometimes it is the little drawings we make in each other's hearts, paintings that will die with us but which we freely photocopy and share with others until, a thousand years later, little versions of ourselves appear screaming from their mothers' bellies to join the dance of life and finally lie with us in the dust.
We will never know.