It was bad enough that my daughter had a "talk" with me about some unwritten rule about frequency of posting pictures with status on Facebook ... but then I found this in my Twitter feed (via @joerominiecki):
"Want to show everyone how freakin' old you are? Keep putting two spaces after periods when you type." Which then points to a Grammar Girl article.
Uh oh, no two spaces? Read the article and you can learn the difference between monospaced fonts on typewriters and proportional fonts on computers. With the latter leading to the "logical" use of one space after a period.
I've been typing (quickly, I might add) since 8th grade typing class. Not sure this can be unlearned.
Separately, the same article also differentiates when an animal is a "who" and not a "that." And agrees the beloved family pet gets to be a who, while you can consider anyone else's pet or random animal a that.