There are two conspiracy theories that I refuse to believe that even the most ardent believers in it actually do believe it Those two are that the moon landing was faked and that the earth is flat.
I am convinced that no one actually believes them. It's just a combination of trolling, entertainment for them, and mental exercise.
A lot of us probably lean towards believing it happened but don't want to be stupid if it's ever discovered they did make it up. Cautiously optimistic?