
Sorry to disappoint but it's too late to put me off balance as I've spent awhile in PRSI forum, so...
I of course learned to type two spaces and think it looks more like A FULL STOP that way, so I dislike forum software and comments software that ditch the extra one. I especially long for the two spaces in long paragraphs; there's nothing to break up a wall of text like the sudden appearance of two white spaces.
Naturally enough in social media, when constrained --by Twitter, or some comments sections with character limits-- I will edit out just about anything that doesn't seem essential in order to make the quota. I've been known to leave out apostrophes from words like "doesn't".
As far as em dash is concerned, I learned to type it as two hyphens on a standard typewriter so I usually still do it that way.
Slightly off topic: wow, out of curiosity the other day, I took the cover off an old Hermes typewriter and stuck a sheet of paper in it and typed "a quick brown fox jumps over the lazy dog".... that old test phrase having at least one occurrence of every letter in the English alphabet. I have to say using a manual typewriter was more work than I had remembered it to be, that's for sure. If were not still playing a piano now and then, I don't know if I'd have had the strength to depress the manual typewriter keys used by the fourth and pinky fingers. Using a computer's keyboard all this time has definitely spoiled me.