[raincole]

Humans have a very strong tendency (and have made tremendous collective efforts) to compress context. I'm not a neuroscientist but I believe it's called "chunk."

Language itself is a highly compressed form of compressed context. Like when you read "hoist with one's own petard" you don't just think about literal petard but the context behind this phrase.

[PantaloonFlames]

We don’t think of petards because no one knows what that is. :)

[KineticLensman]

For anyone wondering, it means blown into the air (‘hoist’) by your own bomb (‘petard’). From Shakespeare