Theory:Doctor Who television discontinuity and plot holes/The Star Beast

• So the one way to fix the metacrisis is to just let it go, and Donna gets to keep her memories. Why didn't she just do that in Journey's End all those years ago?

• How exactly does Donna's metacrisis work? You'd think Donna would only have the Doctor's mind up until the point when she originally gained it during the metacrisis (the mind of the Tenth Doctor and preceding incarnations), but she seems to know his future or at least that he was a woman, something that hadn't happened to the Doctor by the time she gained his mind. Does this mean that Donna gained new incarnations mind's as part of the metacrisis every once and awhile? Or that she gained new parts of his mind once the Doctor reawakened the metacrisis in her? Or something else entirely? Does this also imply that other metacrisis beings that happen to have the Doctor's mind (like the Metacrisis Tenth Doctor) also subconsciously gain memories of the happenings of the regular Doctor?

• How does Rose's age work? Apparently, she's 15. But it's only been 14 years since Donna stopped travelling with the Doctor (yes, I know they SAY 15 years in the episode, but it's actually only 14 because of the the whole 12 months later Aliens of London thing). If you then throw in the End of Time happening ANOTHER year later (and Donna not being visibly pregnant), meaning the EARLIEST Rose could be born in summer 2011, meaning Rose should be MAXIMUM 12, which she clearly isn't (I know Russell T has said he deliberately messed with the timelines a bit in order for him to cast Finney who was 18 at the time, but that's an out of universe explanation, not an in universe one)
  • (Technically Russell T. Davies also somewhat gave an in-universe though he was mostly joking. The in-universe explanation makes mention of a time cloud that descended over Camden and dislocated everyone by exactly eight months and three days. That said, it most likely shouldn't be taken too seriously and even if it was meant to be taken seriously, Rose would at most be 14 not 15.)
  • Rose could have been adopted at an early age. Maybe the baby Donna was pregnant with was given up or didn't make it.
    • If that would be the case Donna would have died after the Doctor reactivated the DoctorDonna and Rose would not have had everything passed on to.

• Why is the TARDIS damaged so much by COFFEE? And, if it was POSSIBLE for it to be damaged to that extent, WHY would it out a coffee machine on the console?

• Why is Shirley Anne's wheelchair equipped with darts and rockets for emergencies but not a motorised engine? Surely, in a situation that would require her to use such weapons, she would also need a motorised wheelchair to allow her to get to safety quickly and out of danger.
  • Because she is a person with free will and chose not to or maybe just didn't think of it.