Warning: here be spoilers. (Though since I am still not entirely sure what Mulholland Drive was about, it is hard to spoil it).
At first glance, Stanley Kubrick's 2001: A Space Odyssey (1968) and David Lynch's Mulholland Drive (2001) are not obviously similar. The first is a science fiction film that covers millions of years of human evolution (in a linear fashion), and explores issues around technology and extraterrestrial life. Lynch's film is a drama set in Hollywood, and is a mysterious neo-noir tale of dreams, reality, and identity. Kubrick's film is famously light on dialogue, while Lynch's film is full of elliptical conversations. However, both films are visually striking, and the story of each is propelled forward by a mystery.
The greatest similarity between 2001 and Mulholland Drive (and is what connected these two films in my mind) is the sudden change that happens at the end of the second act. These changes are triggered by mysterious objects which alter the reality of the previous action. In 2001 the monolith appears throughout the film, slowly influencing the progress of human evolution. Dark, opaque blocks of something, the monoliths have the ability to move around, and even communicate with each other, implying an inherent consciousness and intelligence (or that they are controlled by beings that possess these qualities).
Astronaut Dave Boorman, who is part of a space mission to Jupiter, encounters one of these monoliths orbiting the planet. It transports him through space and time. He then finds himself in an 18th century style room where he watches and experiences his own 'evolution,' as the ageing process is sped up, assumedly by the monolith. Boorman is re-born a Star-Child, a new, uncharted phase of life for humans.
In Mulholland Drive, early in the film, Betty and Rita discover a blue key in Rita's purse. There is no hint as to what it opens (nor does Rita remember why she has it). After a bizarre performance at a club called 'Silencio' Betty and Rita suddenly find a blue box in Betty's purse. How did it get there? Moments before Rita opens it with the key, Betty disappears from the room. Opening the box triggers a sudden change in the plot: the characters Betty and Rita change to Diane Selwyn and Camilla Rhodes respectively. Other characters from the film appear but all the relationships have changed; and places previously visited are visited again but have different emotions attached to them. A cafe that was the scene of dialogue about dreams is now where Diane (Betty) hires a hit man to kill Camilla (Rita). Another blue key is mentioned in this scene: the hit man says she will find it on the table when the hit is completed.
The mystery surrounding these two objects also connect the two films. In neither 2001 or Mulholland Drive is it explained where they come from. The monolith simply appears on earth in the first act, then another is uncovered on the Moon, another orbiting Jupiter, and it is the last thing that Dave Boorman sees as a human. One could assume that it is some type of alien life, but its motivation is not obvious. We also do not know if it is benign or malevolent. Perhaps it is simply a conduit for supremely evolved beings to influence other lifeforms. Who knows.
Because Rita is suffering from amnesia at the beginning of Mulholland Drive she cannot explain what the key is for. The mystery of the box's appearance in Betty's purse is also never explained. The second blue key that appears in the third act is somehow related, but again the 'how' is not obvious. As it is a key that unlocks a box, it is tempting to read them as a metaphor for Rita unlocking the truth of this world: that it is in fact 'untrue,' a fabrication. Is identity something we fabricate for ourselves? And if so, are our ideas about other people also creations, even acts of private storytelling?
Perhaps the strongest connection that these two movies have is that they are to be experienced rather than explained. Because of this, they stand up to multiple viewings as audiences try to decipher what they mean. (I will use this as an excuse if this post is hard to follow: it's the fault of the films, I tell you!).
Like many great films, 2001: A Space Odyssey and Mulholland Drive ask us questions about who we are as a collective group, and how we relate to each other within that group. The questions are not easy, nor do they necessarily prompt positive answers.
To be clear, I am not suggesting that you actually watch 2001: A Space Odyssey and Mulholland Drive back-to-back. I believe that would leave you mentally spent and highly confused. After both I needed time to absorb what I had seen (and occasionally heard). If you are the type of person who likes things neatly wrapped up at the end of your movies you will probably be mortally frustrated by them or rather bored.
If you have seen them, what other films did they remind you of?