Think of a grain of sand.
Just a millimetre squared piece of dirt. Maybe it’s pink, translucent, black, brown, red, lying beneath many other grains. On close inspection it’s unique, but at a distance it’s the same as the rest of the beach.
One of many.
It would not be missed by the child playing on the sand, but it would be missed by those closest to it. There would be an absence, an emptiness, where it had been but was no more.
To those closest we are unique and uniquely missed when we’re gone, even if only by one.