Katherine Rooks remembers when she first learned that a punctuation mark could wield a lot of power.
The Denver-based writer had sent her high school-aged son a text message about logistics — coming home from school.
"I could tell from his response that he was agitated all of a sudden in our thread. And when he came home, he walked in the door and he came over and he said, 'What did you mean by this?' "
Rooks was confused. How could an innocuous text message send confusion?
"And so we looked at the text together and I said, 'Well, I meant, see you later, or something. I don't remember exactly what it said.' And he said, 'But you ended with a period! I thought you were really angry!' "
Rooks wasn't angry, and she explained to her son that, well, periods are how you end a sentence.