Lister and his friend Chen had a theory that there were two seperate beings who existed inside the human mind: Confidence, who tells us "You're great, you're dead sexy and everybody loves you" and Paranoia, who says "You're stupid, you're useless, you're ugly and everybody hates you". Lister's Confidence was very strong, but his Paranoia would take over at inappropriate moments and ruin his plans.
When Lister contracted a mutated strain of pneumonia, his hallucinations began to take physical form. One of the dreams he had was of his idea of confidence and paranoia. When the fever broke, Rimmer informed Lister that two men had materialised in the Drive Room: One was Lister's Confidence personified and the other was his Paranoia.
Confidence was a large man who looked like the manager of the London Jets. He had slicked back hair, very white teeth and wore outrageously coloured clothes and lots of jewellery. He spoke with an American accent that made him sound like Bing Baxter, a famous quiz show host. Both Baxter and the Jets manager were people that Lister associated with self-confidence. He had a large appetite, eating an enormous fried breakfast as soon as he appeared.
Full of energy and enthusiasm, Confidence loved spending time with Lister and told him constantly how great he was. He even picked up Lister's cigarette butts as evidence that he had met Lister, "The duke of deliciousness". This positive reinforcement and encouragement made Lister very happy and even increased his intelligence to the point where he could figure out the location of the hidden hologram personality discs.
When Rimmer discovered that the Medicomp had been sabotaged, he accused Confidence of damaging it deliberately to avoid Lister getting better from his pneumonia. He also looked for Paranoia, but couldn't find him anywhere on board. Confidence helped Lister retrieve the discs from the ship's outer hull during a space walk, but then admitted casually that he had smashed up the Medicomp and then killed Paranoia, putting him through the Waste Grinder and flushing his remains into space. When Lister mentioned wanting to get inside so he could safely remove his stuffy spacesuit, Confidence then tried to convince Lister that they could breathe in the vacuum, removing the helmet of his spacesuit. He promptly exploded due to the pressure differential. (RD: Confidence and Paranoia).