The em dash and I
A defence of the most misused mark in English, from someone who has drawn several hundred of them.
The em dash is accused of being lazy — a comma that got ambitious, a colon without the commitment. I draw them for a living, and I think the accusation has it backwards.
Used well it is the only mark that carries the sound of a thought changing direction mid-flight. Used badly it is a shrug. The difference is whether you needed the interruption or just could not decide.