From Wikipedia (link: http://en.wikipedia.org/wiki/Have_one's_cake_and_eat_it_too):
To wish to
have one's cake and eat it too or simply
have one's cake and eat it (sometimes
eat one's cake and have it too) is to want more than one can handle or deserve, or to try to have two incompatible things. This is a popular English idiomatic
proverb, or figure of speech.
The phrase's earliest recording is from
1546 as "wolde you bothe eate your cake, and have your cake?" (John Heywood's 'A dialogue Conteinyng the Nomber in Effect of All the Prouerbes in the Englishe Tongue') alluding to the impossibility of eating your cake and still having it afterwards; the modern version (where the clauses are reversed) is a corruption which was first signalled in
1812.
Comedian George Carlin once critiqued this idiom by saying, "When people say, 'Oh you just want to have your cake and eat it too.' What good is a cake you can't eat? What should I eat, someone else's cake instead?" Of course, in the original correct form (
eat your cake and have it too), Carlin's critique does not apply.
Have Your Cake and Eat It Too is a book by
Susan G. Purdy.
Bob Dylan changed the phrase in his song "
Lay Lady Lay" in the line: "You can have your cake and eat it, too." It is also in a song by the
Jersey Boys.