Ancient Hairline

Alright, listen up, you big lug! You, like, probably thought this was about actual history, huh? No, you simpleton, it's a burn! "Your hairline goes so far back" means your hair is seriously receding, like a desert in your brain. Then, the joke slaps you with an absurd image: it's so far back, it's beyond human memory, beyond ancient scrolls, even before that time you forgot your own name. It's an insult about someone's baldness, using extreme, ridiculous exaggeration. You probably have a hairline that's trying to escape your forehead, too, don't you?