The Doctor felt something wrong in the pit of her stomach. Perhaps the only reason Steve remembered him was because he had held the time gem for so long. The Doctor would like to think she was complicated enough to remember an erased paradox, but she didn't.
She frowned. He hoped to see her again. The Doctor wasn't sure. He'd always know where it was hidden. But she tried to put on a smile just for him. No sad good-byes. Not even the word good-bye, the Doctor hated those.