I consider it a character flaw in my friend. This fellow did things I consider genius. Self taught, mostly. No college.
I suspect that allowed him to think outside the box more than most. But it left gaps in subjects such as physics and orbital mechanics.
It does not change our relationship, except I ignore the obvious blind spots.
It's really a matter of who, and what, you trust. You didn't go to the Moon; neither did I. So first-hand knowledge is not available to us.
There are really two questions at hand:
1) Is it physically possible to "go to the Moon"?
2) Has anybody ever actually done it?
(1) Can be answered, to a certain extent, by observations that are within the capability of most folks of reasonable intelligence who have the time to make them. Nothing particularly "modern" is required; Isaac Newton and Johannes Kepler would certainly have had something to say about it.
(2) Is a bit more complicated. Since only a double handful of men have ever claimed to have accomplished the feat, it falls to trusting them, and the tens of thousands of people who helped them do it ... Are they trustworthy? Is the physical evidence they provide credible? A generation raised on "Fake News" and systematic lying in high places may, perhaps, be forgiven its doubts. I seem to be finding more reasons, every day, to detest the liars in Big Government and Big Media.
think outside the box
Unconventional thinking has its merits. It is at its best, though, when based on an understanding of conventional thinking. If we all had to start from zero, we'd get nowhere. One of our great strengths, as a society, is our ability to build on the knowledge of our ancestors. "We stand on the shoulders of giants."
It does not change our relationship
Nor should it. Friendship is vastly more important than trivial disagreements.