Have you ever been to a party where you didn't know anyone?

Have you ever been to a party where you didn't know anyone?

An quittance of Joe said: "Have you ever been to a party"

Joe responded: "yes"

The Acquaintance replied: "Yeah but like one where you were randomly invited and didn't know anyone there"

Joe quickly replied: "Yeah, I have actually"

The Acquaintance said surprised: "Really? which one?"

Joe: "My schools' after prom party".