lol so much stuff kinda doesn't make a lot of sense in light of this. why didn't Clara see any Doctor before Hartnell when she was inside the Doctor's entire timeline in The Name of the Doctor? why did the explorer Timelord arbitrarily put a limit of 13 regenerations when she could have given her people literally infinite life? The Last of the Timelords hinted pretty heavily that exposure to the Untempered Schism was what made Gallifreyans into Timelords, which I always really liked, but I guess they just take children and show them the continuum of time itself for no reason? and what's the probability that the Doctor has never encountered her pre-Hartnell self in her thousands of years of travelleing, and then encounters one like a few weeks before she learns about all her past lives? idk, I'm not someone who's obsessed with continuity to the most minute detail, and this show is kind of designed to be constantly remade, but this twist seems pretty close to show-breaking imo. moreso because it fundamentally changes the Doctor's arc in a way I'm not sure I like and can't really be undone. I care a lot less about The Brain of Morbius finally making sense than I do about the wonderful arc from Hartnell to now being lost.