By the Gods!

Luciano Marin watches as Maciste (Reg Lewis) shows how to start a fire in COLOSSUS OF THE STONE AGE ( aka Fire Monsters against the Son of Hercules)

I always see these scenes in stories set in prehistory. In this instance, Maciste (named Maxus in the English version) shows the tribe how to start a fire. They all cheer when it happens (below). It's always one person teaching another tribe how it's done when I believe everyone pretty much knew how to start a fire. This was the entire plot of QUEST FOR FIRE (1981). Cave people weren't that dumb. But the whole  debate is still on-going.