Yes, most of us have a concept of those things. We also have a concept of how many times since then the government has said 'totally doing it again for reals this time you gusy! Just a few years1!'
Most people do not have exposure to rocket ship construction. Building construction yes to a certain extent, they can see a building go up. Most don't watch a rocket ship being designed or manufactured.
The only conception, which I think is the one you are referring to, is that things often take longer than announced.
Wasn't really clear you were talking about that when you only talked about the timeframe it would take to get to space. It sounded like you were saying people don't know how long it took us to get to space last time.
Only because he demanded it. Those of us actually working on it just had a bunch of extra work to do indulging his fantasy while simultaneously doing the actual work of reality.