I think it is natural that when people read a book, they wonder to what extent writers have cast themselves, family members, friends or acquaintances as characters, perhaps with an agenda in mind.
Some friends who have read my novella, "Manhattan Morning", have expressed surprise to discover that neither I nor anyone else they know appears therein. The main characters -- Dan, Marcy, Gloria and Rev. Saddleford -- are inventions I set in motion and who then, to at least some degree, took on lives of their own during the writing process.