aliensspace

Everytime Kochanski is mentioned before series VI, she's described as being Lister's crush, the one he never got to have because of the drive plate incident. It's implied they didn't know eachother much, and she becomes the symbol of what Lister could have had

Then, in Psirens, after 200 years in stasis, the narrative changes, and she now used to be Lister's lover, not only according to him but to the others as well. In that same episode, her original actress is brought back to play a Psiren impersonating Kochanski

Which brings us to Ouroboros, in which a different Kochanski -played by a different actress- is brought onto Starbug. In her universe, she used to date Lister, and caught him smuggling Frankenstein onto Red Dwarf, and she ended up taking her and being sent to stasis instead of Lister

Now here comes my potential explanation for the conflicting backstories (not that Red Dwarf ever cares about continuity): During the 200 year stasis before series VI, Starbug ended up colliding with Kochanski's universe, which, due to some instability or other, gave Starbug's crew memories from Kochanski's crew, making them believe Lister and OG Kochanski dated there too. This would also explain Lister recognising her despite her looking very different from OG Kochanski