First time in a long time that he'd gone out of his way to try to change something wrong in the universe, and it went lopsided. He owed some man with a convertable a ridiculous amount of money, missed lunch entirely, and in the end he didn't even manage to save the person.
Cordelia Chase Bloom.
Who was she? What was she like? Did she have a pair of red sneakers when she was a child? Did she smudge her mother's lipstick across her face and try to be a grownup? Did she do well in school? Did she like chips? Play a sport? Get acne? Have her heart broken? Raise a child?
In the end, he figured it was better that he didn't know. Couldn't see a face that wasn't saved, didn't have a memory of her at all. Memories, they were the sort of things that ate at him. He never forgot anyone. Ever.
The Doctor was in one of those moods.
Bag of groceries in one hand, box of chips in the other, he pushed his way into the TARDIS, glancing around the console room for his blue companion. Was she still mad at him for failing? Oh, probably. His mind was a bit too focused on his next destination to really care. She'd get over it, she always did. Furious as all hell one minute, then a few moments later she'd just act as though nothing was wrong.