"So, you're the twelfth Doctor?" asked the Companion.
"Yes!" said the Doctor, a twinkle in his eyes. "Well, no. Actually, I'm the thirteenth. I just don't count one of my lives."
The Companion scrunched her adorable face in a look of mild confusion. "Why?" she asked. "Was he evil, or aborted?"
"Oh, no!" said the Doctor, his eyes still twinkling a little. "In fact, I consider him very much a Doctor. In a way, the old fellow was more a Doctor than any of me. I told him so, once. Though I thought he was a bit of a bastard for quite a while before then. My memories were wrong, you see."
The Companion didn't see.
"But I worked it all out during my last life," continued the Doctor, "So now I fully acknowledge him as a Doctor."
"So you are the thirteenth Doctor!" said the Companion, prettily satisfied with herself.
"Well, sort of… technically," said the Doctor, his eyes now only vaguely twinklish. "But I was used to the numbers I'd set down, so now I just say I'm the twelfth."
"That makes no sense!" said the Companion, sipping tea with one hand and idly pressing buttons on the TARDIS console as she sat right on top of it because there wasn't a proper chair nearby. "Why not just admit that you're the thirteenth Doctor?"
"Oh… because I'd made T-shirts," admitted the Doctor with some reluctance. "You see, I support myself by selling merchandise across time and space. Posters, papers, pens… Do you know how awkward it would be to muddle the numbers now?"
The Companion seemed rather disillusioned. She shrugged her shoulders, however, resigning herself to another slightly cynical reality. "At least that's a reason," she said, "even if it's not a good one."
"All my reasons are good," retorted the Doctor, his eyes not twinkling even slightly (though his manner was nonetheless charming and whimsical). "But… I'll acknowledge that some are better than others."
"All right, we'll drop the subject. I just wanted to know how many lives you've had." The Companion slipped her svelte frame off of the console, toggling a few switches with her bum on the way down. It didn't matter.
"Fourteen," said the Doctor.
"What? Fourteen what?" The Companion threw her tea into the air, where a miniature black hole appeared just long enough to suck it into another universe, staining Omega's tunic.
"I've had fourteen lives," he replied.
"But I thought you said you've been thirteen Doctors!" cried the Companion, stomping a girlish foot. "Are you joshing me?"
"I never josh!" declared the Doctor. "But my tenth self -- who was actually my eleventh, but never mind -- he pulled a bit of a trick and regenerated into himself after the energy healed his wounds."
"You can do that?" asked the Companion, suitably awed.
"Certainly, if I have a spare body part in near proximity."
The Companion gave the matter a bit of thought. "So," she said slowly, "What's the point of changing into someone else at all if the regeneration simply heals you first? Why is mutating into another person even part of the process?"
"Because Rassilon was a prat, that's why," replied the Doctor. "He was always adding unnecessary steps to the Time Lords' biological processes. It's why I have to scream into a bag every time I go to the bathroom."
"I was wondering."
"An excellent habit." The Doctor reached into a miniature black hole and retrieved the tea. "Just don't go too far with it. Our universe is full of things which don't make sense."
"Like you claiming to be the twelfth Doctor on his fourteenth life rather than just admitting that your number's thirteen?"
"Yes, quite. But shush!" he cried. "It's an unlucky number! Don't you know I’m superstitious?"