[this is a response to a deleted post suggesting Neil Armstrong, Buzz Aldrin, and Michael Collins went along with a moon landing farce for fame and riches]

The actual story is probably much more sad.
Someone at some point must have come across or discovered the impossibility of sending a sufficiently shielded vehicle through the Van Allen belts with current technology. They went to their superior(s).
But already there were ulterior motives. Already the fix was in. A few accidently in the know were reminded of their NDAs / "national security" and told to keep their heads down and keep working.
The gears spun up the new plan. Increasingly aspects of the program became compartmentalized.
The left hand didn't know what the right was doing. Any frustration was met with the explanation that this was all for security reasons. We had to take measures to evade Russian espionage, you see?

At some point the chosen astronauts were secluded to the dry run of the Serious Simulation™. They were given a playbook to follow for broadcast purposes and some exercises to perform. This was all to be ready for the real moon landing. They were prepared with the understanding that the importance of the program required a certain degree of theatrics and they may as well learn their marks on the ground. After all - even if they do pull this thing off they will need to secure the following year's budget from congress.

The simulation / dress rehearsal goes from stage to stage - from performance to performance. The astronauts are really ready now. They're even pulling off the publicity measures that will help NASA's future. And when it's all said and done some high ranking official takes all three men into a debriefing room and explains the situation.