If it's possible to watch a movie without thinking about it too much, I don't wanna know about it. Sure, most movies can be viewed in a daze or drunken stupor and still prove entertaining, but there are lots of motion pictures out there that reward viewers for obsessing over them in ways that probably warrant a trip to the mental health clinic afterwards. Thing is, filmmakers love to include little jokes, references, moments of foreshadowing or plot-based clues for people to discover during a second or third viewing - it'd be rude not to acknowledge them. And if there's one thing I hate, it's rudeness, which is why I've assembled 10 amazing hidden clues you probably never noticed in classic movies - clues that directly refer to moments that occur later in the movie, cleverly sum up entire plot points, or secretly explain everything you wanted to know about the ending of a flick in a single sentence. Sometimes they even offer us up extra information. In most cases, these little gems have simply been overlooked by the population at large, given how tricky they are to spot... how many did you already know, then? Please note, there are spoilers for all the movies included on this list contained within.