You can't have your cake and eat it  You can't have your cake and eat it (too) is a popular English idiomatic proverb or figure of speech. The proverb literally means "you cannot simultaneously retain your cake and eat it". Once the cake is eaten, it is gone. It can be used to say that one cannot have two incompatible things, or that one should not try to have more than is reasonable. The proverb's meaning is similar to the phrases "you can't have it both ways" and "you can't have the best of both worlds." For those unfamiliar with it, the proverb may sound confusing due to the ambiguity of the word 'have', which can mean 'keep' or 'to have in one's possession', but which can also be used as a synonym for 'eat' (e.g. 'to have breakfast'). Some find the common form of the proverb to be incorrect or illogical and instead prefer: "You can't "eat" your cake and [then still] "have" it (too)". Indeed, this used to be the most common form of the expression until the 1930s–1940s, when it was overtaken by the have-eat variant. Another, less common, version uses 'keep' instead of 'have'. Choosing between having or eating a cake illustrates the concept of trade-offs or opportunity cost. An early recording of the phrase is in a letter on 14 March 1538 from Thomas, Duke of Norfolk, to Thomas Cromwell, as "a man can not have his cake and eat his cake". The phrase occurs with the clauses reversed in John Heywood's "A dialogue Conteinyng the Nomber in Effect of All the Prouerbes in the Englishe Tongue" from 1546, as "wolde you bothe eate your cake, and have your cake?". In John Davies's "Scourge of Folly" of 1611, the same order is used, as "A man cannot eat his cake and haue it stil." In Jonathan Swift's 1738 farce "Polite Conversation", the character Lady Answerall says "she cannot eat her cake and have her cake". The order was reversed in a posthumous adaptation of "Polite Conversation" in 1749 called "Tittle Tattle; or, Taste A-la-Mode", as "And she cannot have her Cake and eat her Cake". A modern-sounding variant from 1812, "We cannot have our cake and eat it too", can be found in R. C. Knopf's "Document Transcriptions of the War of 1812" (1959).