Is is one of those episodes that was so important to the show. Not because it was major plot device but because it was an episode that, for the most part, was random yet hit every viewer right in the heart.
Why did no one remember her?
Does this episode show what humans are capable of or does this show a side of the doctor never witnessed before?
that old guy said that he made this trip 14 times. in all those 14 times he never thought to ask the hostess what her name was?