Author`s Note: So it was my birthday, and I got thinking about the Doctor and his age and does he ever celebrate and I got bit by the fanfiction bug. This was originally meant to just be a oneshot, but it kind of grew. There are a few other parts to this, yet to come, but this fairly short little bit of randomness was something I just had to write. So here you are, and I hope you enjoy An Excuse to Eat Cake.

Additional Author's Note: So it's been pointed out to me that Rose already knows the Doctor is 900. Well, TOUGH. Huffy fanfiction writer, aka me, has decided that, for the purposes of this daft little story type thing, she DOESN'T already know. So nyah.

Disclaimer: I don`t own Doctor Who. If I did, my name would be plastered over the credits and I wouldn`t be writing here, scrounging for reviews. Not that I don`t like writing here...

Meaning

Rose was staring at him again. "What is it this time?" he asked, sounding a lot more exasperated with her than he actually was.

She wrinkled her nose at him. "Oi, no need to take that tone with me, mister!" She laughed before she resumed her staring. "No, cos I was just thinking... You said you're an alien, yeah? And you also said you're, like, really old. How do you keep track, though? Cos travelling around like this, I mean, what counts as a year?"

The Doctor's face darkened. It wasn't her fault, she was still pretty new at this. She couldn't have known just how much that actually hurt, thinking about his age. Usually he kept track of it based on Gallifrey Standard Time, but since the War... well he had sort of lost track.

"Rose Tyler, I have no idea how old I am."

"Don't be ridiculous!" she laughed. "Mr. 'I can feel the turn of the Earth and see all of time.' You must be able to at least tell how old you are."

It was his turn to stare at her. Why the sudden concern with his age? Well, he might as well decide something. He had definitely lost track, but he figured since he was in his ninth body, the number nine seemed like a good jumping off point. "Nine hundred years old. I'm nine hundred."

She just gazed at him incredulously. "You're joking."

He shook his head. "Nope. Dead serious. Would I ever lie to you Rose Tyler?" Yes, he would. Repeatedly. It was Rule One, though she didn't know that.

"Blimey," she boggled. "And to think, my mom's worried about forty." She paused for a moment and regarded him. "You don't look nine hundred."

"Well, I am."

"Do you ever celebrate birthdays?"

It was his turn to marvel. "What for?"

Rose shrugged. "Why not? It's a good way to mark how old you are. And a good excuse to eat cake, I suppose."

The Doctor shook his head. "Humans. Always trying to make sense out of chaos, celebrating insignificant milestones like the date of your birth. You know what? How about you show me how it's done. We can go visit your mother on her birthday and we can have a proper celebration." He winked at her. "Also I kind of want some cake now."

"Alright then." She was beaming at him. "Tell ya what though, better make it her thirty-ninth. I've got a feeling she really doesn't want you witnessing her turning forty."