In 1961

...futurists imagined that the milkman would have a robot "dobbin" that would follow him as he made his rounds.  Courtesy of Paleofuture.

What they did not imagine was that kids today would wonder, "What's a milkman?" 

When I was a kid, the milkman and the eggman both made home deliveries.  They came down from the farms on the hill or from the co-op.  (My mother also took us on weekly hikes to the corner grocery story, to Korte's meat market, to Thatcher's fish market, etc.  There was also a weekly farmers' market in Centre Square.)  The milkman is long gone now, and from a confluence of multiple factors:

1. Reliable electrical refrigerators meant that frequent deliveries of fresh milk were no longer necessary.  
2. The movement into the suburbs meant more travel time between houses, adding to the cost of home milk delivery
3. So-called "super markets" combining grocery store, meat market, fish market, bakery, et al. into a single establishment made milk available on one's regular market trips.  



Stan Schmidt writes of the convergence
of multiple strands of techochange

4. The personal automobile enabled housewives (yes, housewives) to make such market trips to the central super market and carry large amounts of food on each trip.  

Futurists often see tomorrow's technology as merely enabling or improving today's practices and customs.  Whatever we do today, we will be able to do faster, cheaper, better tomorrow.  But in fact, we will generally do something else entirely.  The confluence of multiple changes creates complex feedback loops and synergistic effects.  This is also what makes central planning a mug's game.  Imagine government planning in the 1950s for the future of the home milk delivery process! 

[O]ne of the games to which [the human race] is most attached is called … “Cheat the Prophet.”  The players listen very carefully and respectfully to all that the clever men have to say about what is to happen in the next generation.  The players then wait until all the clever men are dead, and bury them nicely.  Then they go and do something else.  That is all.  For a race of simple tastes, however, it is great fun.

– G.K. Chesterton, The Napoleon of Notting Hill