What is reality? The question has plagued mankind for thousands of years, but to date, no philosopher has yet provided a definitive answer. Lazy philosophers... Fortunately for us, film makers have taken one for the team and tackled this huge debate themselves, exploring issues of perception and understanding through the medium of cinema. Have you ever watched a film so disorientating that you yourself have questioned what reality truly is? Fans of science fiction (or drugs) should know exactly what we're talking about here, but if not, then prepare to have your mind blown by these 10 movies that will make you question your own reality. However, if you're the kind of movie fan who constantly asks everyone in the room for clarification while watching films, this list may not be for you. Aren't those people annoying? Just watch the damn film already! Remember to let me know what you think of my choices once you've finished reading and if you've still got a grip on reality, feel free to add some more selections in the comments section below.