Exclamation Mark (!)

From the title (on Netflix it's shown as just "!", not text) I initially couldn't figure out what the topic was. When I did, I thought "Wait, what? They must have run out of things to explain."

However, despite this initial scepticism the episode is quite interesting and educational. The history of the exclamation mark is not a dull one and the producers have done their homework, showing how its use in literature and general print has changed over time.

We also see influence of social media where the exclamation mark has taken on a new meaning, being more a tone indicator than a form of punctuation.