“One should always be a little improbable.”

“One should always be in love. That's the reason one should never marry.”

“One should absorb the colour of life, but one should never remember its details. Details are always vulgar.”

“One should always play fairly when one has the winning cards.”

“I should fancy, however, that murder is always a mistake. One should never do anything that one cannot talk about after dinner.”

“One should always eat muffins quite calmly. It is the only way to eat them.”

“The proper basis for marriage is mutual misunderstanding. The happiness of a married man depends on the people he has not married. One should always be in love - that's the reason one should never marry.”