Principal photography of this film took over one year. Because all cast and crew members had other full-time jobs they were only able to film on Saturdays about 15 minutes of footage until photography had been completed.
The alias used by Bill in the bar is Danny Lloyd. Danny Lloyd is the name of the actor who played Jack Nicholson's son in Stanley Kubrick's "the Shining". Christopher Nolan is a fan of Kubrick and considers him to be one of his primary influences.
Christopher Nolan never studied film-making at university. He studied English Literature at University College London, he used the film society there to shoot the opening dialogue scene between Bill and the policeman.