TIL about how the term hackneyed came to be. I figured it was related to Hackney in London somehow, and knew of hackney horses and that London cabs are called hackney carriages/cabs...
Turns out it is related to those.... they became so commonplace (and worn?) that they term hackneyed came into use to describe that concept.
there are many sites with this info, here are two
http://www.worldwidewords.org/qa/qa-hac1.htm
http://www.word-detective.com/2015/10/hackneyed/
Not an amazing discovery, granted, but someone might find it interesting