I don't own Doctor Who. I don't know if someone has done this before, but I decided to do it after realizing that technically, Rory is probably older than the eleventh Doctor.
"So, where to next?" the Doctor asked Amy and Rory as he dashed around the TARDIS console, grinning like a mad man. "How about we go to the moon and have a picnic? I think I could extend the TARDIS's force field to surround us outside. Or what about we visit Einstein, you two would love him!"
"Or how about me and Rory go get some sleep?" Amy asked quickly, causing the Doctor to stop.
"Sleep? Why do you need to..." the Doctor began asking, before realizing. "Oh. I've kept you two awake for awhile haven't I?"
"Just a bit." Amy said, while Rory nodded.
"Oh, well, in that case you know where your bedroom is." the time travelling alien told them, and the married couple walked up the nearby stairs with a polite nod and goodnight. He watched them disappear into a corridor, before setting the TARDIS to the moon. After all, why should he miss out on a picnic because his human companions needed so much sleep?
Two hours later, after multiple trips to and from the moon in a desperate attempt to stop rogue sontarans from blowing it up and sadly having lost the picnic basket, the Doctor walked into his TARDIS to find Rory staring at the controls, wearing his dressing gown. When the doors closed, Rory looked at the Doctor in surprise.
"Oh, sorry." Rory said quickly. "I couldn't sleep, so I came to find you and ask if you have some coffee around here?"
"Coffee? Who wants coffee?" the time lord asked as he walked towards the console. "You're British aren't you? Shouldn't you know that tea is better?"
"Yeah, well, I got stuck in America while guarding Amy for a few years. I think it was the sixties? Anyway, I developed a taste for coffee." Rory explained, causing the Doctor to pause when he saw something. A strange look in Rory's eyes, one that seemed to be familiar to the time lord for reasons he couldn't understand.
"So I know I've already asked this before, but how much do you actually remember about that time?" he asked, trying to sound casual about it.
"What time?"
"Being the last centurion." he clarified.
"Oh. Bits and pieces really. The important moments." Rory told him. "Sometimes I remember more and other times I can barely remember any of it. Like I said, its like a door in my head."
"Do you think about it often?"
"No, not especially." Rory replied, before growing very silent. He looked down for a moment before looking back at the Doctor. "Can I ask you something?"
"Yeah. Anything you want to ask, just ask."
"It's just that when the memories are especially clear in my head, I look around and I just feel so...old." Rory finished, at which point the Doctor realized why he recognized that look. That was the look of a man who had lived far too long and seen far too much. It was at this point that the Doctor realized that he wasn't the only old man with a young face on this ship.
"And I was wondering," Rory continued, "if you ever felt like that."
"All the time." the Doctor admitted.
"Will it get easier?" Rory asked. "I mean will I one day, when the memories become clear again, just feel the same as I normally do?"
"I don't know." the Doctor replied. "I'm only nine hundred years old, give or take a few centuries. You lived for nearly two thousand years Rory, one thousand and eight hundred and ninety-four years if you want to be specific. You never slept or had anyway of making time go faster. I don't know if you ever will just act like the same old Rory when those memories become clearer. You might always feel older than you look."
"Like you?" Rory asked. When the Doctor nodded, Rory continued questioning him. "Then how do I not go crazy from it all? From all the memories and the feelings I get when I look at someone older than me and think of them as a child in comparison to me?"
"You just will Rory." the Doctor told him firmly. "If you weren't prepared to deal with all of that, you would have gone crazy a long time ago. But you stayed sane for two thousand years as Amy's protector. I think you can handle the memories."
Rory was quiet for a moment, before nodding. "Thanks for the pep talk."
"Any time. Now go get some sleep. You still haven't made up for all that time you spent awake and as a doctor, I can assure you that two thousand years of sleep deprivation isn't healthy." the Doctor joked, making Rory laugh.
Tell me what you think and if there are spelling mistakes.