Rose Tyler & the Twelfth Doctor
The Doctor didn't like being corrected, but he did like hearing Rose laugh. So, in defense of himself, he tried playing the clown to get her to laugh more. "Train of thought? Why would it be train of thought? The thought process is more like a ship on a sea of consciousness. Thoughts are fluid. And an iceberg?" Without skipping a beat, he told her, "Icebergs is like writer's block!"
Lukewarm? The Doctor's smile faded momentarily. He wondered whether or not she'd think he was cool if he were younger, in the body she was most accustomed to traveling with, and almost asked, but decided against it. Rose Tyler was not Clara, who couldn't accept the older face of his new regeneration. He'd let it slide, though he couldn't help but feel sadder.
"Fine! I'll tell you my name," said the Doctor, rolling his eyes. "I'm Professor Basil Disco, and now you know why I always tell people to call me just Professor!" He nearly gave his usual alias of John Smith, but he realized that it would be too much of a giveaway.