When filming the Pepperpot Lifeboat sketch, John Cleese needed to shoot his line several times because he kept vomiting due to sea sickness. After filming, he and writing partner Graham Chapman were driving back to town. Chapman, who had trained as a doctor, told Cleese that he should have something in his stomach after being sick. Cleese replied that he fancied some cheese, but they couldn't find any suitable shops. Cleese asked Chapman if he thought the chemist's (pharmacist's) might have some cheese. Chapman joked that they probably only have medicinal cheese. Cleese joked back that Chapman could write him a prescription. The Cheese Shop sketch that appears later in this episode was thus born. During the writing of the sketch, Cleese kept asking Chapman if he really thought what they were writing was funny. Chapman kept motioning for Cleese to continue, assuring him that it would be funny. Cleese remained uncertain until the weekly writing meeting when they read the sketch out to the entire Monty Python troupe. Michael Palin, according to Cleese, fell out of his chair laughing.
John Cleese has often said that the only sketches of his from series three that he thought were any good were 'The Cheese Shop' and 'Dennis Moore.'
Biggles is not an original Python creation. The character comes from a series of popular adventure stories about a brave RAF pilot named Biggles, though the original Biggles is certainly not as silly as the Python version. This might be why his secretary refers to him as a "fictional character."
Sam Peckinpah reportedly enjoyed the "Salad Days" parody and later became friends with fellow heavy drinker Graham Chapman.
Given that the Cheese Shop sketch stars John Cleese, it is interesting to note that his family's surname, prior to his birth, had actually been Cheese. His father changed the family name when he enlisted in the First World War, finding the name to be embarrassing.