Disclaimer: I recently read an article explaining why some professional writers don't like fan fiction. So let me just say, I am not profiting off this, I'm not trying to force my views on anyone else, I'm not trying to discourage anyone from watching Doctor Who. Quite the opposite in fact. These are my musings about Doctor Who and are shared to stimulate thought and encourage discussion. (Long disclaimer, I know. Sorry!)
A/N: As said in the summary, this was written before season 6. I think everything else is self explanatory. Please review!
How old was he? That was the million-dollar question, wasn't it? That and what was his real name. He grinned as he tied his bowtie (he didn't care what Amy said; bowties are cool), only a small handful of very special people would learn his name (who in the cosmos was River, and how did she know his name?), but NOBODY would ever learn his age. Honestly, he didn't know it himself. Oh sure, he had told Rose he was in his nine hundreds, but he had also claimed that he was thousands of years old when he was only in his third body. The truth was that he had lost count almost as soon as he had left Gallifrey. Between living in the Tardis where the concept of time changed (really, he could only keep track of time in the Tardis based on how long his companions stayed), and the length of years on Earth being different from the length of years on Gallifrey and so on, well! It was a wonder he had been able to remember to say nine hundred to Rose every time it came up (though he suspected he screwed up once or twice and added a year or two to the age he had previously told her). Then there was the matter of birthdays. Who knew how old one was when one did not celebrate one's birthday in what felt like eons? Not that he ever really celebrated his birthday; it was just not done in Time Lord society (after all, it's not like the person did anything to merit a celebration, they were just born, and everyone did that). And even if he had wanted to share his birthday with his companions, the date was based on the Gallifrean calendar, and that died right along with its creators.
He finished tying his bowtie (they were still cool, and it would have been even cooler if he still had that fez!), grabbed the box next to him, and exited the Tardis. The surprise birthday party Rory had planned for Amy was already in full swing, with Amy sitting in the middle of all the excitement looking a little annoyed at all the attention, but at the same time incredibly happy. "Oy, Pond!" he shouted to her. Amy looked up. "Happy Birthday!" He grinned and tossed her present at her. She opened it up and, after seeing what was inside, beamed at him. "And here's to another few years of travel, at least," he whispered.