Someone said that if you reverse the dialogue, it’s basically the same. Of course, then I had to try that. It’s. So. True. I didn’t even realize until now that they were both doing that to each other, and they didn’t see how it was affecting the other. Clara I bet barely remembered Oswin or ClaraOO, maybe not at all. The whole time, Eleven thought of her as a girlfriend, or at the beginning a good friend. But he mentioned a dead version of herself, and I bet when she said “I never thought you were,” she meant it. She probably thought the Doctor was keeping her because he wanted to be reminded of the mysterious girl who he mentioned, but even though that hurt, she loved him enough to stay with him. Then, Twelve probably thought all Clara wanted was Eleven when she was starting to see him as a new person, yet the same one at the same time. He was prepared to let her travel with him for as long as she wanted, no matter if all she wanted was Eleven; because even still, he’s still a little bit of Eleven, and he couldn’t possibly leave his impossible girl.