Fact from fiction

Writing is both imaginary as well as factual. Writing is about yourself but much of it is based on the fiction of storytelling which is a disconnect from the real life story but still relies on the real life component, you, to tell it and you tell it with the real life you so mixed in with the fiction such that it's difficult to tell where the one starts and the other leaves off.
A good story has to grow with a life of its own, the moment of your writing, the creation of a character and their story as it unfurls is what makes it real and the biographical aspect which is the source of the ingredients you add to the dish is not the finished product by any means.
Creativity is to walk the walk with your character, to envisage how their day and the issues that arise in it can seem real.  They have an ingredient which everyone recognises as real and possible. The genius of a writer is to create a complex "who done it" without it being a crime story, simply a life story as it unfurls with the scrapes and escapes which we all get into and which makes our lives hopefully rich and liveable. 
To believe the story you have to believe in the character and to believe in the character they have to have a component that most people can relate to. 
Your knowledge is based on the people in your own life, they with all their warts and disfigurement,  they contain the texture of what you know about real people, not the idealised person you might wish to imagine they were. 
If I were to write a story about Swansea and set it amongst the wet, tiered, bleak housing which makes up parts of the town and add the unrelenting grey wet sky which presses down on the spirit each day as the wind loosens the refuse bags of their rubbish, strewing the paper and discarded bits of flotsam which make up our lives, onto the street further depressing the landscape. Its then that I can introduce the first of my fictional/factional characters, perhaps as they step out of the door, up the steps to wrestle with the gate which still needs fixing. The character begins to walk and eventually talk, first to themselves and then to someone they know standing on the corner, sheltering from the rain. Both conversations are rich in opportunity. The internal one relates to what happened last night when you were out in the town and here lies the crux of the story the second is based on the reality of carrying on, regardless of the great secret which burdens the teller.
And so a story unfolds carrying the reader with its plausibility and the potentially unspoken crisis. There is one in all of us and we want to read about others which are similar but oblique to our own, comforted to know we are not alone.
There can be only so many story lines but the writers tapestry is emblazoned by the craftsman-ship of the weave and the colour which make it stand out.
I have to emphasise that I have never tried to write fiction although perhaps my imagination and a wide pallet of experience from across the world would provide the seed corn for a story or two.
My guru has become Philip Roth and his fund of personal experience. Growing up as a Jew and assimilating his objective persona with the subjective baggage of his tribe. His tussle with who he was to become through the indoctrination of his upbringing and the realisation that not every-thing could be contained in it. His intellectual journey is too engrossing to feel limited by his birthright and whilst it provided a yardstick it was not the whole measure of the man.