The first attempts at street lighting by electricity imitated the moon: big tower, bright light on top. Shadows and other problems led to our current lighting systems.
"Beer and bread" was a greeting in Ancient Egypt -- rather like wishing someone "Good luck."
Armor was not driven off the battlefield by firearms. It could withstand the firepower of its day; a standard test was to shoot a gun at it. But the size of the armor made it too expensive for it to be practical to armor them all.
Nineteenth-century Americans attributed the English settlers unwillingness to intermarry with Indians to their superior race and the consequence racial pride. (Seems to have more to do with settlement patterns.)
Thrushes can catnap for as little as thirty seconds and be refreshed.
"Charles," "Karl", "Carolus" -- all these names and all their variants merely mean "free man." Indeed, "carl" -- or "churl" -- was commonly used to indicate the class that while higher than the thralls, was definitely lower than the "jarl" or "thane." Nevertheless it was first recorded for a king, and has been very popular with kings.
The disappearance of the Neanderthal is correlated with the time when you stop finding as many large game animals -- like deer -- and more small ones --like rabbits -- around human camp sites.
Suicide rates in the United States fell after Pearl Harbor.
Heraldry, unsurprisingly, arose in the Middle Ages after the knights started to wear full-face helmets.