AAAARGH! Am I the last person on the Internet to learn that modern typography calls for just one space after a sentence, not two? In my defense, yes, I did learn to type on a manual typewriter, which had a monospaced (fixed-width) Courier font. On the other hand, I have been writing and publishing on the Internet for more than (hmmmm) sixteen years! To learn exactly why the double space after a period has been abandoned, here are two articles. The first is from Grammar Girl: How Many Spaces After A Period?. The second from Slate: Space Invaders: Why you should never, ever use two spaces after a period.
But back to my original question. Am I the last to know that a period should be followed by a single space, not two?