One of the wonderful things about writing fiction is that we have complete freedom to be as honest and blunt as we feel is necessary to get across an idea. The reader never knows which bits of a story are fictitious and which are true. There is an immunity to story writing which nonfiction does not have. The latter can, generally, not maintain the same sort of freedom due to concerns of hurting others or defamation lawsuits.
Fiction writers tend to use people they know or have known as the basis for various characters in their books. It may be only one particular part of someone or an event which is used. Other times, the real-life character is so perfect in his or her ability to represent themselves that no change is deemed necessary or advisable. It is natural for writers to use their own experiences as that is how we make sense of life and relate to other people. Having said that, I do not think writing is a rational or deliberate process. I never decide who is in my stories. That would be like deciding who we are going to have a relationship with. With seven billion people in the world, would it not be wise to let Life decide who of those people belong with us? With an infinite number of ideas swirling around us, would it not be wise to let Life decide which of those ideas are ours? Stories write themselves, if we let them.
I have come to the conclusion that writing fiction is a joint venture. The people we use in our stories “help” us to write by adding their unique energy to the creation of a story; not just the energy that comes from recalling someone but, rather, the actual life-force that radiates from that person. It is a co-creation. Life is a mass of intricate, intertwined energy systems. Their seeming invisibility does not negate their reality or power. Everyone is blessed for the contribution they make. Life, in the biggest sense, is fair, inclusive, and generous.