Most of the traditional terminology of grammar derives from the art of public speaking, technically known as rhetoric, a rhetor being someone trained & skilled in public speaking. A ‘period’, that is, a discrete, defined segment of time relates to the expression a specific, standalone thought or idea, otherwise known as a sentence. A ‘period’ therefore indicates the completed expression of an idea, and a momentary pause for breath. I hope that helps to make the inexplicable more explicable 😉🤣.

I'd make some sort of wise-crack about how we must have a lot to celebrate over here, but then I remember the House Freedom Caucus's apparently unstoppable quest to shut down our entire Federal government. At least they haven't yet decided we must to refer to periods as "full-stops." Slainte' mhaith!

Living in the USA, but of Scottish ancestry, I find it interesting that there is a National Punctuation Day. I also have a degree in Journalism, so I was taught the importance of punctuation. Unfortunately, many people in the USA no longer learn or understand the fine points of punctuation. Sad.