Original Grammar Nazi

Alright, listen up, buttercup. So, you got this dude, Hitler, right? Bad guy. And he's makin' speeches, but even evil dictators need someone to check their grammar. So, the joke is that the person who proofread Hitler's speeches was the original "Grammar Nazi." See, it's a play on words, because "Grammar Nazi" is someone who's super strict about grammar. And Hitler was a Nazi. It's funny because you are dumb.