Cognac is brandy, which is distilled wine.
Technically, to be called cognac, it must come from an area around the town of Cognac in France, and indeed they make some fine brandies there. But other brandies can be good too, and might cost significantly less.
The sky is my jewelry box, the clouds are cotton puffs.
The birds and stars are rings and other shining things
Which glisten in my treasure chest.
The lightning is a necklace which a queen would love to wear
And if you think I'm crazy, building castles in the air
Well, tell me something better to have going on up there.