Because it is true, it did happen, and there is all sorts of evidence supporting it.
This isn't science. Doubting the Moon landings is akin to a mental illness IMO.
This is exactly my point and sounds exactly like some religious fanatic who's responding to someone who doesn't believe in what they believe in.... it solves nothing in regards to the whole conflict with the moon landing.
Someone doesn't believe the moon landing really occured?
Ok..... ask them the reasons why and give them logical answers that counter their existing claims. If they have a room of error or just assumed to be true due to hearsay, then there's a problem and thus a probability (no matter how remote) for those claims to be false.... which allows the skeptic to hold true to their position until further information is provided.
Just because people don't simply believe what they're told and actually want evidence to form a decent opinion on something, is not a sign of mental illness, in fact I'd say it's the opposite.
They may be wrong in believing the moon landing didn't happen, but their approach isn't..... it's the best way to formulate your own view on something with as much given information as possible.
For me personally, one of the issues that came to me over some of the images of the landing are many photo elements that I had questions about, since I'm a photo editor and graphic designer. At the time I didn't claim the landing never happened, I was just asking questions as to why some things were the way they were.
Instead of getting a logical answer, I got shatted on and finger pointed as a hoax supporter...........
......... that's still not an answer and it sure doesn't help the cause of proving one way or another, let alone helped explain the things I was wondering about in regards to issues in photography and film. All that looks like is a closed frame of mind, unwilling to explain what they believe in, which raises more qustions.