Banging with rocks is out of date. We now bang nails with concrete — that way you can cement your banging tool out of any pebbles you like. Sure, sometimes one

Banging with rocks is out of date. We now bang nails with concrete — that way you can cement your banging tool out of any pebbles you like. Sure, sometimes one of the pebbles (like the one that keeps the left side of your banging block straight) falls out and gets lost and you can't bang any nails that day, but that's the price of progress.