Heh. That may speak to your youth. It's definitely a thing. There are whole tirades online about spacing after periods, with a general trend that older folks prefer two spaces, and younger prefer just one. C.f. the Carolingian reforms as they applied to writing: a single space between each letter, two spaces between each word, and three spaces between each sentence. Given that the "single space" in Carolingian terms just meant that the letters weren't all running together, we have modern block print as I learned it: letters distinct and separate, one clear whitespace between words, two clear whitespaces between sentences.
The practice of one space everywhere, even between sentences, appears to be a relatively modern contrivance. C.f. these two pages from Ben Franklin's Poor Richard's Almanack, or this page from the 1914 publication Library Jokes and Jottings by Henry T. Coutts, or this page from the 1894 book Benefits Forgot by Wolcott Balestier, or this page from the 1809 book The present state of Turkey by Thomas Thornton, or this page from Charles Dickens' 1853 book Bleak House, all clearly showing increased spacing between sentences than there is between words. HTML, XML, and other markup enforces single-spacing by programmatically collapsing adjacent spaces into one upon rendering. Modern fonts and layout engines theoretically handle kerning and such to adjust spacing between words and sentences, but many don't make any distinction, resulting in effectively the same spacing between words and between sentences. Two spaces after sentence-final punctuation, especially in monospace situations, can make it easier for a reader to visually parse the text, by clearly differentiating gaps between sentences versus gaps between inline words, including abbreviations that might be followed by a non-final period.