Well, I learned something today...and I would've lost money betting on this had someone challenged me to a wager on it.
Years ago in my early teenage years, I took a typing class in summer school. My buddy and I got this idea that if we took a typing class, it would be a class full of girls (it was) and that there we be a lot of returns for the investment of our time (there were--unfortunately, they were all carriage returns). In any case, skunked though we were, I really did learn how to type and it's come in handy now that the predominance of our communication these days is done via a keyboard. I should say, my typing training has come in handy until what I just learned today. There. Right there. I did it again.
It turns out, the typing rules I learned back in the (mumble)-ties are no longer valid. And even more surprising, they were not valid BEFORE the typewriter either. The rule of which I speak is the "two spaces after a period" rule.
This article in SLATE lays out the very well-supported case that I have been wrong about the two space rule, EXCEPT when I was typing on an actual typewriter. So I am now correcting my excessive spacing practice and apologize to all for the years of causing the reader to skip a beat in getting to the first word of my next sentence. And that means that everyone who has been hanging onto this practice--it's time to move on. No one should have need to use a typewriter any more except for eccentric authors or about 20% of government workers still responsible for filling out unnecessary forms in triplicate.