"Steerpike of the Many Problems," said the Doctor. "What did you say they were? My memory is so very untrustworthy. It's as fickle as a fox. Ask me to name the third lateral bloodvessel from the extremity of my index finger that runs east to west when I lie on my face at sundown, or the percentage of chalk to be found in the knuckles of an average spinster in her fifty-seventh year, ha, ha, ha! - or even ask me, my dear boy, to give details of the pulse rate of frogs two minutes before they die of scabies - these things are no tax upon my memory, ha, ha, ha! But ask me to remember exactly what you said you problems were, a minute ago, and you will find that my memory has forsaken me utterly. Now why is that, my dear Master Steerpike, why is that?" "Because I never mentioned them," said Steerpike. "That accounts for it," said Prunesquallor. "That, no doubt, accounts for it."