Post etymologies in any language that you think are very interesting.
“Wild goose chase” actually originated from a type of horse racing, where a bunch of horses had to follow a leader horse in a goose flock formation, and were judged based on their ability to keep formation. The modern meaning comes from the fact that the lead horse could go in any direction and there wasn’t a finish line.
“Quintessential” comes from “quintessence”, meaning the pure essence of something, which comes from its original meaning of the fifth element (quint “five”+essence), aether, which I guess was regarded as the purest element.