You Can't Know Yourself Until You Know This

You are a Eukaryote and you share a common ancestor with every other multicellular organism on the planet. You exist only because an Archaea and a Bacteria merged a couple of billion years ago after approximately 2 billion years of life.

This origin is still visible in your cells where your mitochondria, responsible for cellular energy production still retains its own DNA from when it was the symbiotic bacteria.

You are still a symbiotic ecological system.

Your body contains approximately the same number of cells from other organisms as it does your own, from more than 1000 species, a microbiome. Your ecology is part of the greater ecological system of our planet and just as vulnerable to ecological threats. Your microbiome is inseparable from what you know as yourself.

It influences your behaviour, mood, diet, health, and more through a complex and non-linear system of interrelation. Without microbial life, there is no other life.

You are not an individual you are part of a whole and your health depends on the health of the whole.

_{The Tree of Life}
Image Source Note: I added the "you are here" bit to show approximately where humans are.