What happens is fact, not truth. Truth is what we think about what happens.
We rarely know where we are going; writing is a discovery.
Story is metaphor for life and life is lived in time.
Don't be didactic - don't write about poverty. Write about poor people. When you dramatize their lives and let life and characters be your inspiration, you will express the 'idea' dynamically and without preaching.
Story is about originality, not duplication
Given the choice between trivial material brilliantly told versus profound material badly told, an audience will always choose the trivial told brilliantly.