Privilege

The Twelfth Doctor believed that the value of any given society was truly measured by the value it placed on a life, in particular, one without privilege. His view of progress was one which considered how a culture treated those in the lowest rungs of their society, rather than focusing on mere industry or wealth. (TV: Thin Ice)

Indeed, the First Doctor himself had been born into wealth and privilege. Robin Hood compared his own origins to the Twelfth Doctor's. He understood that, like himself, the Doctor had found it too hard to bear the "plight of the oppressed", and so, refusing to stand idly by, he ran off in the TARDIS to fight injustice in his own way. (TV: Robot of Sherwood) On becoming a renegade Time Lord and running away from Gallifrey in a stolen time capsule, the Doctor's Prydonian privileges were revoked. (TV: Death in Heaven)