Kubrick was killed when he was about to reveal the truth about his film for NASA about the Moon landing. NASA did actually go to the Moon, but they had to hire Kubrick to film the landing because, in reality, they found Nazis there.
This truth sounds like a crazy conspiracy theory, and everyone laughs at it because agents of the lunar Nazis infiltrated the leadership of Israel and the United States, and through their efforts, this truth now looks like a lie.