moon: why go so many times?

i know there's about 3 million other threads out there about the moon landings but bare with me, even though this will probably be moved... if we didn't go to the moon then why would nasa fake so many landings.

some arguements are that only half way to the moon astronauts would have been exposed to deadly radiation. so this imply that we have 'never' been to the moon, thus all the apollo missions were faked that landed on the moon. what about apollo 13? if they weren't sending people to the moon, why was this mission a failure? how can you have a failed mission to the moon when you're faking them on earth?

i believe we did go to the moon, the original footage looking at neil steping on to the surface was real. however, because this footage was grainy i believe nasa felt it necessary to ulter photos. this doesn't mean i'm implying that they got the astronauts in a movie set and took new photos, but that they probably enhanced the photos to make them clearer.

the evidence that we never went to the moon is all hearsay and circumstancial evidence. even if photos were taken from above the lunar surface of the landing sites, what is going to stop people from saying 'but that could be a birds eye view of a set in groom lake...' if we go to mars, again how much proof is needed that we went? what is proof? there are photos, video, eye witness accounts (neil armstrong etc), yet it seems we can't actually 'prove' we went to the moon according to some people.

just some thoughts and questions...