Jenna-Louise Coleman first debuted on Doctor Who in “Asylum of the Daleks” as Oswin Oswald, a human converted into a Dalek. Coleman had been announced as the Doctor’s new companion yet her character inexplicably died. She reappeared in the Christmas special, “The Snowmen,” as the fully-human Clara Oswin Oswald, who is a brand new character according to Coleman. Once again, Oswald ran out of time. “Run you clever boy and remember,” she says with her dying breath. Despite her change in appearance, the Doctor does remember her, which keeps Clara from being a ripoff of South Park‘s Kenny, a character who constantly dies but is resurrected as though nothing happened. The Doctor resolves to find out who she is.
A preview for upcoming episodes shows Clara in a variety of hairstyles and dress that seem to be yet more versions of her, and the line “remember” recurs in a portrait of Clara. The Doctor clearly remembers her by the time she becomes his companion so she must want him to remember something else. Dalek Oswald also said it, which suggests their history could go even further back in time.