Only then can he return to being The Doctor again and move on.
https://www.youtube.com/watch?v=6o5F7cWL6SoVideo can't be loaded because JavaScript is disabled: The Doctor Forgets Clara | Hell Bent | Doctor Who (https://www.youtube.com/watch?v=6o5F7cWL6So)
Series 10: Back to Basics
BBC
Moffat planned to leave the end of Series 9 and 'The Husbands of River Song' would have been his final chapter,[...]
