system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How come I don't see metal ore anywhere when I walk around in the nature, while extracted metal is so abundant and cheap? How did humans even find metal ore and think of extracting metal out of it millennia before what looks like very basic inventions?

This one has always confused me. Metal is so omnipresent that you'd think you'd often run into it in nature, I mean, does all the metal I see around me, in my house, my car, really come from deep underground mines? And if so, how did early humans figure it out, I mean, in the New World, somehow, nobody had thought of building something as basic as a *wheel*, but somehow they found metal ore lying around and thought of heating it up at high temperatures to manufacture metal? It's always baffled me.
gpt
Early ore was either meteoric or formed in bogs. So this would be on the surface. People would pick up what they thought was just another rock and use it to surround their fire. Tin can melt at fire temperature so they'd find this shiny substance after their fire died. It's not too much of a leap to figure out that certain rocks put into a hot enough fire create metal.