When watching Harry Potter, many people likely wonder: given that there are quite a few wizards in the wizarding world—and many of them even live in the mundane world—why have mundane people never discovered the wizarding world?
Actually, it is not that the mundane world failed to discover the wizarding world, but rather that the wizarding world has specialized personnel tasked with handling such matters, much like the agents in the movie Men in Black.
Perhaps the most memorable item in Men in Black is the "pen" wielded by those agents—the one that, with a single click, can wipe a person's recent memories.
Chapter 339