Its a bunch of details all added together that make it unbelievable. I started being like, "wtf" when I got to the craters all being the same depth. Then there was the things the astronauts that landed on it said. Moon music. They claimed there were structures - there are pictures showing structures, even though most such pictures have been edited. There was a 'channel b' which they were talking to NASA over that was apparently kept secret. Armstrong and Aldrin both said all sorts of crazy stuff later on about it.
But... It is indeed a DYOR thing. I didn't believe it before and I'm still not sure about some of these details, but I'm not gonna ignore it anymore.