Mmm... something to go along with the Impossible Face theory. What's more, it'd also be a reason I would have a human body here. If the stories from the four people here who have travelled with the Doctor is anything to go by, he's a troublesome do-gooder who's been able to save a lot of people. Imagine trying to keep someone like that under lock and key in this place.
... and yet that just makes me think I might not be that same man.