Jack is a recurring character in my stories because I'm lazy. It's easier to remember the name of just one protagonist, and he's developed a bit of a personality that I enjoy carrying along, here and in galaxies far, far away. Jack tends to have a variety of adventures: many of them prurient, often with young partners, and not necessarily in the context of previous stories. Some other narratives don't mention him at all, or he may be only peripheral.
The author's name is not Jack, although his bio parallels Jack's in several respects. Well into his eighth decade, with something like 20 years of school behind him in bits and pieces, he has found time to be an ocean lifeguard, soldier, pilot, policeman, teacher, writer and editor, along with a few side jobs and diversions. He lives in Florida.