Well, Silverysky, I’m amazed too and not ashamed to admit it!
The fact that a collection of cells - some with ‘our’ DNA and some not - can come together, cooperate and compete in a complex way, and ultimately give rise to an integrated and coherent sense of selfhood is amazing.
For me, the sense of self is due to incredibly complex information-containing patterns in the brain. This sense of self can survive the substrate that holds the pattern completely renewing itself. In other words, the molecules can be replaced but the information content persists, at least for a while.
We’re all rather like ripples, eddies, vortices embedded in a universal matter-energy sea, constantly forming and dissipating from the same stuff, convinced by the illusion of our separateness.
On a rather less cosmic scale, I’ve got a small bottle of Multibionta in the kitchen. It’s chocablock with ‘foreign’ DNA but I never feel an assault on my selfhood when I take a tablet! It’s fascinating to think just how much bacteria can influence our experience of being ourselves though. Most of the body’s serotonin is produced in the gut. The bacteria in the gut can influence serotonin levels and thereby mood and behaviour.