"Perfect!" The Doctor beamed suddenly, rather liking that last bit. "Which means I won't remember running into you. Oh, good. It's worse than running into a former companion, at least they're all temporary in the first place. Why did you use my title earlier? Koschei never does. Never did."
He scowled, shoving his hands deep into his pockets.
"Don't actually know what happened to him, but he's the hero. Glad he is. He's a better hero than I am. Always has been. Better for people."