Disclaimer: I do not own any of the characters in this story yada yada yada, I don't own the series Dr Who, yada yada yada. Etc etc unlimited rice pudding (hehe, neither do I own that quote)!
The Doctor leans against the TARDIS console in the control room waiting for Rose to get back from her Mother's, absent mindedly he reaches into one of the inner pockets of his coat and pulls out a small black disc with a carving on it. He starts to flip it from his right hand to his left hand and rub it betweens his fingers.
He had been young and foolish then, not knowing what he was doing. Though he would never have admitted to being so, or not knowing anything, least of all something in the realm of the day-to-day business of a primitive civilisation. Perhaps there was something in it, or perhaps it really had all been a dreadfully embarrassing mistake. She had been so intelligent, and wise. Old with wisdom yet young at heart, like him she had known love and loss and had withdrawn in the ashes, only to be rekindled by one like her.
Those cocoa beans had been a simple thing to turn into a delicious drink, not knowing that they could be turned to bitter use in the breaking of the heart of a friend lost. He couldn't have stayed with her if he wanted to, not forever; but he could have lingered a while. He could have stayed until in the passing of time she had faded, like the one before her, but it would have hurt too much.
She couldn't be much more different this time, eager to learn everything there is to learn, so full of energy to keep going from place to place, seeing all there is to see, so young that she could be shown so much in the time allotted to her. But nothing lasts forever, not even a Time Lord. He himself didn't have long left now.
"What's that Doctor?" Rose asks as she slips into the ship unnoticed by the Doctor in his musings.
"Oh, nothing. Just something I picked up from my travels." He lies. "A long, long time ago."
"So are we going to go then?" She pesters.
"Going?" He mutters. Yes he shouldn't have gone, he should have stayed, but there would have been nothing for him eventually.
"Hello? Mr Daydreamer? Are you going to take me to Barcelona or not?" She calls in one ear, half expecting it to come reverberating out the other and around the seemingly infinite lengths of corridor in the TARDIS.
He puts the coin reverently back in his coat pocket. "Ah yes, Barcelona." He mutters.