Tropes

Joker (2019) :

Sorrow & Hate – the Joker is unsuccessful in the love he tries to bring to the world. He struggles with mental illness and works a low income job. You feel sorry for him as his living situation is a very real one for many people. His hate develops as a result of being pushed to the outskirts of society.
Metaphor: Mental Illness / Clowns – a clown is often seen as happy and fun but in fact, they only try to make other people happy, not themselves. Furthermore, clowns can not express their true emotions as they are constantly wearing a mask that shows joy. They are disallowed from showing their discontent; which leads to bottled up emotions and declining mental instability. The extended metaphor of clowns and mental illnesses is a comparison between an entity that is presumably happy and stable, when in reality is depressed – much like a mental illness that on the surface seems manageable, but beneath the surface is destroying the human.