Can someone please explain why the Eleventh Doctor can age 200 years within the same body, but the 8th doctor has to regenerate, because he’s “wearing thin”? Does a time lords body age or not? Normally we’d say it can’t, because he is 1000 and something years old, and it’s difficult to cram that into 11 human livespans and then they never stay until they’re old. So isn’t the fact that the 8th doctor basically *dies* of old age a major fault in continuity?
I imagine they age slowly (explaining how to cram 1200 odd years into 12 lifespans. And I read it as being a death/regeneration brought on by emotional trauma. In much the same way as a physical trauma brings on a regeneration for others, the emotional weight of the war and the ethical crisis he went through burnt out all the life left on that body. It was time for a new chapter.