Yeah, like that iNow guy!
We, however, can locate in the brain where ideas reside. We can even reconstruct visual, auditory, and textual experience from brain activity.
The problem of non-existing referents is actually a big problem in the philosophy of language. And, like a lot of open questions, just about everyone has a different "answer" to it.
"The present king of France is bald." Is that sentence true or false? There are quite a few philosophers who would say neither since there is no present King of France and the sentence thus fails to refer (since "present" is an indexical, though, one could hop in a time machine and make it true or false for those philosophers).
This is actually something that happens in Anselm's Ontological Argument. He starts with the idea of God and then switches to the entity God when you're not looking.