Science or Fiction
“Happy as a clam” was originally, “Happy as a clam at high water” because that is when clams are safe from predators. https://www.phrases.org.uk/meanings/as-happy-as-a-clam.html
The term “nitty-gritty” originally referred to the small debris at the bottom of a slave ship, and then came to refer to the slaves themselves before ultimately evolving to mean tiny details.
The term “bury the hatchet” derives from Native Americans, who would literally bury a hatchet as a symbol of a peace accord. https://www.phrases.org.uk/meanings/bury-the-hatchet.html
Skeptical Quote of the Week.
“Nothing in life is to be feared, it is only to be understood. Now is the time to understand more, so that we may fear less.” – Marie Curie