The Horse's Mouth (1958) starring Alec Guinness
Full of quotable quotes:
"Go away. Scram. Tie lead weights to your feet, fireworks in your hair, kiss your mother goodbye and jump in the river. I don't know you. I don't want to know you. Buzz off! Explode!"
Gulley Jimson: Of course you want to be an artist. Everybody does, once. But they get over it, like measles and chicken pox.
Nosey: But there have to be artists!
Gulley Jimson: And lunatics too! But why go and live in an asylum before you're sent for?
"Go and do something sensible, like shooting yourself! But don't be an artist!"