Because he was taught to talk that way by his parents, who in turn were taught to speak in prisine, posh RADA English by the explorer who discovered them.
Yes. To protect children from the Blitz and remove them from cities likely to be bombed in the war many thousands were evacuated to the countryside. Often they were young and otherwise unaccompanied for this journey and would have their name and details hung around their necks along with a few possesions and a gasmask in a cardboard box.