Here's what 'have your cake and eat it too' really means
The INSIDER Summary:
• It means you can't continue to posses the cake once you've eaten it.
• The phrase makes more sense when you flip it.
There's an idiom that you might have heard before. It goes like this: "You can't have your cake and eat it, too."
It seems nonsensical, right? "Of course you can have your cake and eat it too!" you might say. If you eat something, you're having it! It should work the same way you might "have a beer" or "have dinner." Eating is a form of demonstrating ownership. If you eat something, you posses it.
The phrase, as the linguistic historian Ben Zimmer wrote in The New York Times Magazine, makes more sense when you reverse the construction, so it goes like this: "You can't eat your cake and have it, too."
In this case, the sequence of the verbs changes and the meaning becomes more clear. Once you eat your cake, you have no cake left. It means you can't eat a cake and continue to posses that cake once you've consumed it.
The use of the phrase, therefore, is to tell someone that they can't have two good things that don't normally go together at the same time, like eating a cake and then continuing to posses that same cake so you can eat later.
By now, the use of the word "have" in the English language has evolved to also encompass the meaning of "eat." "Have your cake and eat it, too" is outdated and perhaps, as Zimmer writes, it's time to retire the phrase.