After my partner and I became stewards of some beautiful land, this has been more in the foreground of my mind.
Each being is a world.
On that piece of land, millions or billions of beings (depending on whether you want to include microbes), live their whole life or significant parts of their lives (birds, mammals).
In each case, there will never exist a being like that again. Each one is a unique occurrence.
And each of them experiences the world in their own way. They are, quite literally, their own unique world. A world that has never existed before, does not exist anywhere else, and will never exist again.
Remembering this is very moving for me. It fills me with reverence to be a temporary steward of this land and do my part in protecting it and supporting it to regenerate and rewild.