How easy would it have been for von Braun to say, "When Saturn V comes fully on line, we'll be able to go to the moon!" When he talked about Saturn V he was not keeping it a secret. His job as architect was already essentially a completely done deal.
Saturn V was only used for lifting into Low Earth Orbit, as Apollo was and as Skylab was also.
Is your answer of what Armstrong was asked, "Why haven't we gone back to the moon in over 50 years?" anything like Neil's first-hand-knowledge answer?
About 400,000 engineers and technicians would disagree with you.
On January 10, 1962, NASA announced plans to build the C-5. The three-stage rocket would consist of: the S-IC first stage, with five F-1 engines; the S-II second stage, with five J-2 engines; and the S-IVB third stage, with a single J-2 engine.[27] The C-5 was designed for a 90,000-pound (41,000 kg) payload capacity to the Moon.[27]
The C-5 would undergo component testing even before the first model was constructed. The S-IVB third stage would be used as the second stage for the C-1B, which would serve both to demonstrate proof of concept and feasibility for the C-5, but would also provide flight data critical to the development of the C-5.[27] Rather than undergoing testing for each major component, the C-5 would be tested in an "all-up" fashion, meaning that the first test flight of the rocket would include complete versions of all three stages. By testing all components at once, far fewer test flights would be required before a crewed launch.[28]
The C-5 was confirmed as NASA's choice for the Apollo program in early 1963, and was named the Saturn V.[27] The C-1 became the Saturn I and C-1B became Saturn IB. Von Braun headed a team at the MSFC to build a vehicle capable of launching a crewed spacecraft to the Moon.[19]
The first flight of a Saturn V rocket was an unmanned flight in 1967, and subsequently 12 more rockets were launched between 1967 and 1973, carrying Apollo missions and the Skylab space station. Each rocket took different amounts of time to make, but the first one took about five years of research and development.