The period in the middle of the 20th century is known as the Golden Age of aerospace. It is not at all surprising that a successful crewed mission to the Moon came out of this.
There's one argument that points to the sheer scale of the Apollo project and rightly asks how such an important secret could be kept successfully by so many people for so many years, or alternatively how so many people could be so effectively fooled for so long into thinking they weren't really doing their jobs. There's another argument altogether that asks how named individuals like Maxime Faget and Tom Kelly could have acted in such a scenario.
The people who were tapped out to build Apollo were chosen because they were already at the top of their game and would go on to stay at the top. Tom Kelly was legendary, and the engineering team he assembled at Grumman was separately legendary. Of course someone like
@Vixen who hasn't worked in or studied this field won't know any of these names or reputations. But well-informed people do.
Was Tom Kelly ignorant of what it would take to build a lunar lander? Was his team? Was Kelly fooled by a smarter person in the field (of which there were probably only a dozen such examples)? Was Kelly convinced to risk a successful, illustrious career at the top of his field by participating in a hoax? Would his team have known?
"But Jay, you're just hero-worshiping," has been the answer so far. No, I'm giving demonstrably accomplished people their due respect and rightly questioning the ignoramuses who come along and say he's some kind of poser or fraud, providing no information for it than their own ignorance and incredulity. Yes, I believe such misinformaton should be challenged, and a skeptics forum is an ideal place to do it.