Discontinuities and Incongruences: Part 1

Have you ever wondered: What is language?

I once thought that language was based on commonly agreed-upon nomenclatures and syntaxes.
For instance, no means no.


But recently I've come across this conversation

Friend, "I stayed at home last night."
Me, "So you didn't attend the reunion?"
Friend, "Nope."

Sounds normal. But is it?

In this scenario, instead of "Nope", my friend should have answered "Yes."
Because what he really meant was: "Yes, I didn't attend the reunion."

Yet if someone actually said, "Yes." in that situation, it would have been unconventional. i.e.

Me, "So you didn't attend the reunion?"
Friend, "Yes."


So what happened there? Does our intuition correct for common grammatical errors by logical inference? How did this flaw originate?


This is just one of many anomalies in this world.