No, Iron age is somewhat fluid concept.
In Americas, e.g., it never happed. The Natives lived in stone age until Europeans arrived.
Stone age persisted in Australia, Africa and e.g. Hawaii until Europeans arrived there too.
While Iron age officially ended in Mediterranean well before Trajan emperor, the Germanic Iron Age in Scandinavia actually lasted until AD 800.
Iron is extremally useful thing, strong, plentiful and easily workable.
But the technology of turning Iron ore (basically mixture of Iron oxides with lots of impurities) into workable iron is Very tricky. The, now forgotten, person who first discovered it, was an genius who advanced humanity thousands of years ahead.