I couldn't find a writer who was from a very happy background with all his needs and wants satisfied.
A writer happens only when there is scarcity;
Be it in any manner, say- family, finance, love, friendship or anything that makes an empty space in his heart giving room for loneliness which ends up in imagination...
This imagination shifts him to a different domain, of which he is the sole artist to carve and create characters, situations and emotions.
Only when stressed there is a flood of emotions and only then these emotions could be expressed in the form of an art or writing.
He gives life to a whole new world he finds to escape from the despair of the real world his body belongs to.