Jacques Lacan

Lacan's originally proposed something known as the "Mirror Stage", which is supposedly the early parts of an infants development from 6 to 18 months old. The theory goes that once the baby sees itself in a mirror, what it sees is then thought by the brain to be the perfect image, and so throughout the life of the child from early years to adulthood it seeks out this perfection but can never achieve this perfection. This then led Lamac to go onto to create the idea of "Lack" as in to lack something, and so by the brain lacking something it causes desire to arise. It is this desire that is said to drive a human and keep them going as a human can't live without desire, so the desire has to be something unrealistic so that they never reach said desire because if they do achieve what they want then they won't have anything driving them to achieve something and life then becomes pointless to them.

We can apply Lacans theory to the movie 'Whiplash', in which we follow a boy try to achieve his desire of being the best drummer