
There's no definitive canon explaining how Hope knows what a modern day punching bag is.
She has, however, been spending a lot of time watching movies. The only confirmed movies are the original Star Wars trilogy and The Phantom Menace, but still. She might have watched Rocky.
Note to self: If I want Hope to quote Rocky, I now have the perfect excuse. Not that I needed one, but hey, I have it. Or maybe I do? It's just occurred to me I still haven't seen Rocky. I don't know if this sort of punching bag is in the movie. I'm just assuming there is. But there's gotta be one, right? It's a boxing movie! Right?
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WELL I GUESS I HAVE TO WATCH ROCKY NOW
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