I believe the moon does affect game movement to some degree but I take the solunar theory thing with a grain of salt... I've killed deer on 1-star days and not seen a thing on 4-star days. Other times it's been right on the money. Lots of times I'll check the solunar calendar after the fact, just to see if the predictions match with what I saw in the field. In my experience it's been very hit and miss. And of course I can't see the whole woods from one stand, could be they're moving just as predicted, but just not in front of me. Who knows? Plain old luck plays a big part in hunting success.
There are so many variables though, as others mentioned, weather, wind, humidity, hunting pressure, etc. I work a full time job and run two small businesses of my own in my 'spare' time lol so I hunt when I can, I've never let a poor prediction stop me from hunting, and I've never killed one from the couch.

For me hunting is an escape, a way to get away from it all for a while, relax, disconnect, think things through, etc. So if I don't see a deer it doesn't necessarily mean it was a bad day.

Just my .02