Jim: My grandpa fought in the army during World War Two. He was an officer.
Me: Cool, what rank of officer?
Jim: SS.
Me:...
Jim: My grandpa fought in the army during World War Two. He was an officer.
Me: Cool, what rank of officer?
Jim: SS.
Me:...
Listen up, buttercup. The joke is all about how Jim's grandpa was an officer in the SS during World War II. You know, the Schutzstaffel? The major Nazi paramilitary organization under Adolf Hitler? Yeah, those guys. It's funny because it's super dark and unexpected, like finding out your teddy bear is actually a rabid wolverine. You probably thought the officer rank was some cool army achievement, but nope, it's a punchline about being part of a seriously evil group. Stay gold!