Don't even get me started on GPS coordinates

I'll open today's edition of 'Something to file away for the next pub quiz' with a quote from Thornton Wilder's classic play Our Town:

"I never told you about that letter Jane Crofut got from her minister when she was sick. He wrote Jane a letter and on the envelope the address was like this: It said, Jane Crofut, the Crofut Farm, Grover’s Corners; Sutton County; New Hampshire; United States of America; continent of North America; Western Hemisphere; the Earth; the Solar System; The Universe; the mind of God - that’s what it said on the envelope. And the postman brought it just the same."

This is a fine if somewhat flowery example of the way that letters are addressed in New Zealand.  My domestic mail makes it to me with a simple name, street, and suburb or city.  Apparently the building number, apartment number, and post code are optional.  (New Zealand doesn't have states; cities are the primary regional identifier.)  Since there is generally such a dearth of written information on envelopes, I have a great deal of respect for the posties who are clearly able to compensate via detailed mental databases-- and in an urban environment, besides.

Now, about those post codes.   They are four digits long, and range from 0000 in the far North to 9999 in Southland.  They operate much like ZIP codes in the States.   As a kid, I remember having my ZIP code drilled into my brain (Hello, 49812!) and I know I've had my mail returned when I've absentmindedly forgotten to write it.  So why are post codes used so haphazardly in New Zealand?  I think it's a question of cultural uptake.  Post codes were only just introduced in this country in 2008.  People are still getting used to them.  Some people still don't know what theirs is and need to look them up.  New Zealand Post encourages residents to include post codes on our mail in the interest of efficient delivery.  But with the vast majority of domestic mail being delivered in 1-2 days even without post codes, such a promise is small incentive.