what is the meaning of this---"could you have been dreaming" [closed]

what is the meaning of this sentence---``"

could you have been dreaming?

"Could you have been dreaming?" -- Seeing there are several potential scenarios, I will create one and go with it for an answer. A person describes an event and the listener asks the question above. The meaning of the question could be that the person asking is skeptically exploring that the event is too unusual, unreasonable or even expected. For instance, the event description could be this one: "I saw my late grandfather walking through the hallway last night when I startled awake by a noise outside." Then, the question is asked, "Could you have been dreaming?"

Dreaming = imagining. So the question asks if you imagined something (depends on the context).