That was an understandable response by a man who did go to the moon towards someone stuck in a universe bordering on the solipsist.
FACT: You can produce doubt for anything you wish to produce doubt about, including the sphericality of the earth. And there is no amount of evidence which can force you to think otherwise or rescue you from your delusions if you are determined to doubt it, as so many people are.
You choose what world you want to live in. A world of facts? Or a world where whatever you imagine becomes a fact because you have imagined it?
I think one of the most insulting things you can do to the USA is to pretend that one of it's greatest technological triumphs never happened, and maybe that is a clue to the real motivation behind those who propagate this moon landing hoax nonsense.