In some of the earlier seasons of Red Dwarf, David Lister tells of how, as a baby, he was found in a cardboard box under a pool table.
Then at some point in the seventh season, it was revealed that Lister was in fact
his own biological father, conceived by himself and an alternate universe incarnation of his girlfriend Christine Kochanski and then sent back in time to ensure he lived his life the way history played out to be.
Was this something the writers had planned from the start?