That night in that barn, Clara became the voice that set the Doctor on his way. In the distant future, when he is most lost, she becomes the Doctor’s guide. And whenever he forgets, she becomes his reminder that he can be kind enough to make the right decisions in order to find his way back home—the long way round.
Clara answers her own questions, but more importantly, she answers the Doctor’s questions. She is more than just a companion, she is his answer.