Me too.

I suspect I'm older than both of you, but ... nah.

Heathen!

I know; I daren't show my face in town until after dark.

For me it's more about wise stewardship of resources. There's a limited number of spaces in the world, and wasting two of them when one will do is a dereliction of responsibility in my opinion. What will we do when therearenomorespacesleft?

I learned about it when I was learning LaTeX, just to differentiate in my input file from the end of a sentence and the dot after an abbreviation, such as etc. or e.g.