Doctor Who gen (shippy undertones if you're so inclined), 250 words.
Contrary to popular opinion, the Doctor has never forgotten anything. But with so many years of memories it is only to be expected that people, places, events will sift their way to the back of his formidable mind. It’s easier that way, anyway.
He has never forgotten Susan, naturally enough. He sees a thousand girls on a thousand planets that look like her, and each time the memory scorches. She was too young, and each time he feels so very old.
The Doctor has to laugh, really. In one spectacularly bad move, he’s managed to insult the king of the Foamasi and his mother. It’s at times like this he absently wishes Romana was here. She almost certainly would have known that to compliment a woman on this planet was to be really most suggestive indeed.
There’s a mark on the TARDIS now, the only relic of when he burned up a sun, just to say goodbye. He ought to clean it up, repair it. Somehow, he never quite gets around to it.
When he squints, it seems to form the curve of a rose.
He likes to soak up stories at dinner parties on strange worlds, tales of people he never has met and like as not never will. And so, there is a special delight in hearing first the hostess, then her sister, then the scullery maid, and then the butler all extolling the many virtues of Captain Jack Harkness.
Martha Jones stares at him in amazement and growing fascination, and the Doctor smiles. The next in a long line of faces that he will never forget.