Every once in awhile I hunt for arrowheads. A buddy who is very good at it will call me, and off we go to spend an afternoon stomping around in an empty field somewhere in northern Ohio.
Now my friend is very good at this arrowhead business. He would tell me about the glaciers that once covered North America. I can almost picture them. I've seen the dramatic gouges in the ground that created Lake Erie. (They are stll there, in case you are wondering just how old I am.)
But I've found lots and lots of flint. It may not be an arrowhead, but it works for me. It's been chipped while chipping something else - a spearhead, an axe, maybe even an arrowhead. I pick it up off the ground, and rub the dirt off of it with my thumb. I realize the last person to hold my find passed this very spot 2500 years ago.
I get chills.
From somewhere, an ancestor smiles.