Corrected entry: Lister does not seem to know much about his childhood, as he tells several contradicting stories about it. In series 2 Lister talks about how upset he was when his father died in the episode "Better Than Life". It is possible that he was talking about a foster father when he said this, but we learn in the episode "Ouroboros" in series 7 that he was abandoned, and never knew his parents at all. He also said in series 7 that he lived with his granny too, which leaves the question that if he knew his own granny, then why didn't he know who his parents were? Three different stories of his childhood.
Corrected entry: During the episode "Thanks For The Memory" in series two after Rimmer realizes that some of his memories where actually Lister's he says "no wonder I remember having my appendix out twice" (or something like that) meaning that Lister has had his appendix out. But during the episode "Legion" in series 6 Legion takes out Lister's appendix.