Single versus double spaces after periods

I’ll admit it, I learned to type wrong. I put two spaces after periods when I’m not consciously thinking about it (which is most of the time) which is pretty much incorrect in modern times, as I understand it. It’s a relic of monospace typewriter fonts, which require it for visibility. It’s also good practice in the digital world when using monospace fonts. But outside of a terminal, most people never really do use monospace fonts (like Courier, for example). With kerned fonts it’s considered unnecessary and incorrect, I’m told, and is especially un-OK on the Web.

Well, I’ve put two spaces after every single sentence (except at the ends of paragraphs, of course) on this blog so far, and I apologize. But while for short posts like this I have the willpower to stop myself, I’m pretty sure for long posts it’s going to be the same story. I will, however, begin to do what I should do with other documents (although I don’t typically), which is to correct my bad habit with software, and do a quick find-and-replace.

I’ll try, and we’ll see how it goes. If all else fails, I can always switch the stylesheet to use a monospace font…nobody doesn’t like Courier New, right?

[Edit: rather ironically, given that this is a post on typography, I submitted it by email which totally destroyed the formatting, so I had to go back through and redo all of the spacing and line breaks.]