Having my cake

I’ve never understood the phrase “You can’t have your cake and it it too.”

What else is a cake used for? If I can’t eat it, why would I want it in the first damn place?

Unless, of course, the maxim means “have” in the carnal sense. In which case I can’t imaging wanting to eat the cake after I was done “having” it.

But I don’t find confection to be a turn-on, much less a sexual partner.

Odd.