For me it is the fact that our blood contains iron. I earlier used to believe the word stood for some ‘organic element’ since I couldn’t accept we had metal flowing through our supposed carbon-based bodies, till I realized that is where the taste and smell of blood comes from.
I seem to have made a mistake then. Thank you for correcting it.
Thinking about it further, if we’re talking about stars that we can see with telescopes, Hubble, James Webb etc, then you’re on the money. Stars in remote galaxies far outnumber the ones in our galaxy and show us glimpses of the early stages of the universe. And many of those stars are long gone