The spread of Iron Smelting and Blacksmithing during the Iron Age could have led to a much more widespread familiarity with technology among the general population, than had been the case during the preceding Bronze Age. Although mining of ore and production of iron products was often under the purview of powerful business entities and state authorities, iron can also be obtained by small groups and in informal contexts, and there is evidence that this sort & level of activity was present. The shortlived and perhaps temporary Norse settlement at L’Anse aux Meadows, engaged in iron-production, in a very isolated and remote setting; a boat-load of hard-scrabble Greenland colonists, recent refugees from Iceland, out exploring on their own. They needed nails for the boat; they made small pieces of iron from local stuff, and beat-out some nails.
Bronze requires both copper and tin to be mined from two different locations, and to be separately transported as a rule to a third location, where the two are alloyed. Deposits of both these metals are unusual occurrences, and restricted to certain districts, very widely separated. These conditions favor large-scale societal organization & authorities, and make small-scale and local operations unlikely. Iron changed, even partially reversed, those relative advantages & disadvantages.
Iron ores, unlike copper & tin, occur practically everywhere. With iron, the ore-deposit is comparatively insignificant because they are common. Small, local occurrences are characteristic of iron, so access to the raw material cannot be controlled.
In the case of bronze, typically the mining was an unfortunate fate; a special class of people such as prisoners of war or slaves being sent to the mines, perhaps as a one-way trip. With iron, actual mines were often not developed, since the required quantities of ore could be gathered in an off-hand manner. Local members of the community were assigned to fetch ore, and to cut wood and make charcoal … and these would be the same individuals who would be relied upon to do other necessary work. The iron ‘miner’ might also plow the fields, milk the cows, and thus was not ‘disposable’.
So the plowman and the milkmaid and other average members of society would in rather far-flung & diverse contexts & districts, often be closely privy to the secrets of wresting shiny, strong metal from the earth … and everything that would imply.