I didn't mean brought up by your parent, I meant its been ingrained into your mind because its a prevailing theme in various forms of literature, especially in entertainment media. You've seen movies and tv shows where the wolfman chnages on a full moon or similar stories.
You would be hard pressed to prove that 50% figure with any empirical evidence. Its confirmation bias at its best. It happens to everyone, though.
I don't deny that a lot of it will be rooted in my brain from an early age it's just hard to pinpoint how much of it. I did notice a difference for sure, it was a lot more prominent and I'd be like wtf everyone is going crazy, I'd look up at the sky and there you go - full moon.