[gordonhart]

Miles didn't click for me until I learned that it's defined by how far you'll travel in 1,000 paces (where a pace is an L+R step). Now I find it very useful to convert steps<>distance traveled, which is actually quite useful if you walk a lot!

[zzzoom]

You'd have to be quite tall to average an ~80cm step. 193cm (6'4") according to a quick search.

[gordonhart]

The original unit was the [slightly smaller] Roman mile which was standardized with the military in mind, i.e. able-bodied men in their prime. Seems like the average for men today is 2.5 feet or so which is more or less still on the money for 2k steps/1k paces to a mile.