Have One's Cake and Eat IT Too

That one cannot have one's cake and eat it too is a popular, and correctly quoted English idiomatic proverb or figure of speech. The proverb means the same as "One can be in possession of one's cake, but is not allowed to eat it." This may also indicate having or wanting more than one can handle or deserve, or trying to have two incompatible things. 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." Conversely, in the positive sense, it would refer to "having it both ways" or "having the best of both worlds."

This concept, known as opportunity cost, is one of the most important economic concepts.

Although this saying is a commonly accepted idiom, it is flawed in its grammatical logic. The act of eating a cake must first involve possession of the cake, therefore the only way to eat a cake is to first have it. Regardless of this logical flaw, the phrase is still popular and is regarded as socially acceptable and understood.