Ok I'm having some weird ass déjà vu and I'm thinking about a derpy homestuck panel of someone throwing something and I'm not sure if it exists or if I'm insane. I ask my friend and she's thinking it's real but we're still not sure. Are we insane?

“Someone throwing something” is waaay too broad. If you can be a bit more specific about your memory I may be able to tell you, since I can think of several instances of doofy things-throwing.