Billy Liar (1963)

Directed by John Schlesinger, Billy Liar stars Tom Courtenay and Julie Christie in a British comedy-drama based on Keith Waterhouse's novel. Set in a Yorkshire town, the film follows a young clerk who escapes the frustrations of everyday life through elaborate fantasies and ambitions of a different future. A key work of the British New Wave movement, the film combines humour, social observation and coming-of-age themes while exploring dreams, responsibility and adulthood.

Från IMDB:
A lazy, irresponsible young clerk in provincial Northern England lives in his own fantasy world and makes emotionally immature decisions as he alienates friends and family.