There is a moment when we realise we have been sold a promise that cannot possibly be fulfilled. While the experience extends far beyond cinema, one scene from Sam Mendes' 2007 film Revolutionary Road highlights it well. Blue-eyed and cleanly shaven, Frank Wheeler (Leonardo DiCaprio) radiates a muted charisma as he pauses on a balcony of New York's Grand Central Station. Thousands of unremarkable businessmen in their grey flannel suits and secretaries in sensible heels – the movie is set in the 1950s – stream past this handsome stranger, unaware that he stands apart from them. He is important. He desires something more.

What we see in this moment is the promise that cinema simultaneously gives and takes away. While we long to be stars, we can only watch films as spectators. Hollywood attracts us by implying that we are special, unique and different from the masses. But, at the same time, it requires us to view this message as passive observers in a crowd, a practice without which the cinema cannot function as a mass medium.

There is nothing special about Frank in the scene. He wears the same dull suits with white button-ups and maroon ties as every other businessman passing by. What makes this character unique is the movement of the camera swooping into the station and capturing the angst he feels being unappreciated and misunderstood. This filmic apparatus is the very thing that allows the scene to stand out from the monotonous, everyday drudgery that it seeks to represent.

The blurring of the anonymous masses hurrying to catch their trains encourages us to focus on Frank, the clear centre of the scene. At first, the camera tracks left at a low angle, contrasting the tight focus on Frank with the parallax of the crowd in front and behind. Then Mendes cuts to a symmetrical, stationary shot with Frank at the centre, leaning against the balustrade and glowing from the light of the large windows behind him as if in a modern-day cathedral's stained glass altar. Notably, we do not see from a point-of-view shot of Frank looking down at the crowd, nor from a tracking shot aligned with one of the myriad passers-by. Instead, we see from a disembodied, floating eye in the centre of the station. This eye exemplifies what French psychoanalyst Jacques Lacan might posit as l'objet petit a – a concept Lacan insisted remain untranslated.1 L'objet petit a is a sign for the unattainable desire that floats before our faces, tantalising us and disrupting our view of the real, much like Magritte's apple obscuring the gentleman in the bowler hat in his 1946 painting The Son of Man.

Without the camera, Frank is just another guy waiting for his train. With the camera, he is the centre of a narrative in which only he truly matters. At the same time, without the camera we have no film and no narrative. But with the camera, we have a film in which millionaire celebrity Leonardo DiCaprio meets his Titanic (James Cameron, 1997) co-star Kate Winslet to act in Academy Award-winning director Sam Mendes' screen adaptation of Richard Yates' novel. Watching the screen in a darkened room, we feel this paradox intuitively. Audience members are invited to identify with Frank; many of us have also been absorbed by crowds as we make our way from one destination to another. Perhaps other people are fine with their mundane, inconsequential lives. But Frank is not. The spectator is encouraged to respond in kind: we are important. We desire something more.

Sitting in a room with hundreds of strangers aligned in chairs to watch this moment unfold, or sharing the experience with countless other app users around the world, the viewer senses this connection. The scene has little impact without such empathy. A similar process happens in virtually every Hollywood film. Mendes, for example, earned his Oscar for American Beauty (1999), in which an average young woman stares out of her suburban bedroom window, only to be met on-screen by an admiring young man with a camera in a neighbouring window and off-screen by hundreds of millions of spectators sharing in her wanderlust. As soon as we detect this connection with the character, however, a problem arises. Each of us has paid to view this moment and feel some form of validation that we, like Frank, stand out from this anonymous crowd. But it cannot be denied that everyone else is likely experiencing this same feeling. And thus, we are simultaneously unimportant extras for the people around us.

The setting of the film at the beginning of the post-industrial era is important. This is when the realisation really started. There were inklings of it in earlier cinema. But in the post-war American years of prosperity, the years of Madison Avenue men marketing toothpaste and cigarettes, self-help books promising to help us find ourselves and celebrity magazines providing intimate glimpses of the lives of famous lovers, we began to see ourselves in third person. This is when legendary sociologists like C. Wright Mills start arguing that "Nowadays men often feel that their private lives are a series of traps . . . their visions and their powers are limited to the close-up scenes of job, family, neighbourhood; in other milieu, they move vicariously and remain spectators."2

The feelings of anomie that many of us experience today, despite having thousands of followers and myriad "friends" eagerly anticipating our pictures of desserts and our thoughts on the latest presidential idiocy, really began at this point in contemporary culture. It is why Mendes can recreate this post-war story more than 50 years later virtually unchanged and have it continue to resonate. It helps us understand why we now find it difficult to see a meal or a public event in first person, why we now consider our reactions from the measured, disembodied perspective of someone outside ourselves much like the camera hovering in front of Frank in the crowded station. The film, like the novel, works in third person. It evokes the beginning of a view that we have more steadily been adopting with the help of cinema and social media for decades. And it is no coincidence that Frank, a dull, one-dimensional character, as Herbert Marcuse might call him, works for a large corporation similar to IBM that is just beginning to explore how to use and market big data.3

This trope of being alone in a crowd is now cliché; however, it was David Riseman in the 1950s who helped popularise the idea with his landmark study The Lonely Crowd. In it, he argues that Americans are losing "their social freedom and their individual autonomy in seeking to become like each other."4 The assurance that we are each unique, special, and at the centre of the crowd is what Mendes, like all Hollywood directors, simultaneously promises us in Revolutionary Road and then slowly takes away.