I once drank a bottle of some white wine from the central valley, I have no idea what it was, but I had several people taste it in case I was losing my marbles, and it tasted like chocolate. REALLY like chocolate. A white wine. It was not made with any chocolate.

Aromas are just chemicals floating in the air, anyway.

I just read (in a book about scotch) that alcohol can react with a component in European oak to make a chemical that tastes like chocolate. So I'm guessing your white wine was aged for a good while.

Sometimes, yes. Wine can have a very complex flavor profile and at some point, you have to label what you taste and smell using words. Either we go with things we already have to describe odor and taste ("smells like chocolate", or "has a very buttery mouthfeel") or we have to invent new words...

Uh, yes. Or do you mean in wine?

Probably not something everyone would agree was "chocolatey", but the point is that's the aroma or taste the reviewer identifies. If you or I can't detect it, that doesn't mean they were wrong. Maybe we would describe the same flavor or aroma differently. Or maybe our senses would not detect the same chemical they are detecting. Everyone's sense of taste and smell is different.

It's just an image, it's easier to talk with "chocolate" flavour than whatever molecular equivalent it would be, people on this thread are reading way too much into it.