If you really think about it, we barely know anything about Penny from “The Big Bang Theory,” as she doesn’t even have a last name until she marries Leonard. However, one fan theory might just explain why this waitress and struggling actress is able to live in an apartment alone, as well as why she spends so much time hanging out with people she has little in common with.
This theory posits that Penny is actually a government agent spying on Leonard and Sheldon. In “The Staircase Implementation,” it’s revealed that Leonard once dated a North Korean spy and blew up the apartment building’s elevator with rocket fuel, so he easily could have drawn the government’s attention.
Even if the theory seems far-fetched, keep in mind that the show makes it clear that Penny is not stupid. Maybe the babe in the woods act is played up every time the boys descend into science talk, so she doesn’t look suspicious.