"I did you know," said the Doctor suddenly said as the TARDIS headed to the planet of the shrubs.
"Did what?" asked Clara.
"Try giving it up," he said. "The terrible decisions, the heartbreak of loss. It's not an addiction and those parts I don't like. I got to a point where the thrill of adventure wasn't worth the pain and mistakes and loss."
"What happened?" asked Clara. "What changed?"
He stared at her for a long moment. There was something in his eyes. Love. It was love, she knew it was. "I met you," he said softly.
"Me?"
"An echo. You dream about those other lives sometimes. I know you do. Close your eyes." And she did. He moved slowly behind her, rested his hands on her shoulders and spoke softly in her ear. "Victorian London. You were a governess moonlighting as a barmaid, or it could've been the other way around. You met a lonely man in an alleyway. He helped you escape some sentient snowmen, told you to forget about him, but you were stubborn as always and followed him home. He lived all alone in a box on a cloud, convinced the world was better off without him, that he did more harm than good. For three years I'd been living like that and was determined to keep on that way. But you stole my hearts. You gave me passion again. You convinced me the world needed my help. Do you remember?"
It flashed behind her eyes like a dream. What she could remember most clearly were the emotions. Falling in love. "I do," she said. She felt the Doctor move to stand in front of her again and opened her eyes.
He was smiling at her. "If I have an addiction to anything it's you."
"Ditto," she said grinning. And she knew. It wasn't the adventure she couldn't leave behind. It was him.