if Captain Jack Harkness (John Barrowman's character) stole the name and isn't actually called Captain Jack Harkness, then how come, in the flashbacks in the episode of Torchwood 'Adam', his parents call him Jack? :L
Because his real name might be Jack and he added in Harkness on earth. Did you hear his father say Jack Harkness get over here now! He said it was a convenient maybe that's part of it.
I'm gonna agree with that one. My is Jack, last name came out of a novel I read in '92. Just a coincidence I was known as Captain Jack Harbid more than a decade before Harkenss became a pop icon. If I had a nickel for everytime somone said I was trying to imitate I'd have a sock full of nickles to beat them with ;)
In episode "Adam" The image that he had of his past was created by Adam. Who in fact does NOT know his real name just like the other Torchwood members. So, his parents might have called him a different name. But because nobody knows Jack's real name Adam cant recreate the memory perfectly. Or maybe Jack's parents named him Captain Jack Harkness after the actule Captain Jack Harkness. Just a thought.