Actual proof that this movie existed?

Memory is extremely fallible. I frequently have completely different memories of certain events when compared to the people who were there with me at the time. A lot of people are wrongly convicted based on eyewitness testimony as well. Memory sucks especially when it comes to less important stuff like this. Sometimes when I watch my favorite movies there are "new" scenes that I have absolutely no memory of.

When it comes down to it, your memory is simply incorrect and to think anything else with a complete lack of evidence is simply delusion. In fact, all logic and reason point to the fact that the movie is not real.