Sounds like you write a lot like the long time acquaintance I have. He says the characters come alive in his head and often pester him to write out their story. They write themselves and he just relates them to others. Sarah too jokes about the voices in her head. Characters are residents of the mind.

Me? I gotta wait for others to write those folks out. I’m not creative in that way. It is also fun to get to know more about certain authors and see where some of those characters come from, whether from reality(like reading Travis Taylor and then seeing episodes of Rocket City Rednecks. His Brother-in-law and Rog are in most of the books somewhere and somehow) or from “thin air”.