"Clouds in my coffee"

[morpheme]

Hello! I have a question for many years now...! There's a lyric in Carly Simon's song "you're so vain" that I don't understand the meaning. It says "I had a dream there were clouds in my coffee..." and I think it's an expression but I don't know what it means. I;m almost positive I've seen it elsewhere too but I'd like to learn what this expression means! PS: I'm Greek and it's all greek to me :))

[Wraith]

Don't know if this helps, but CLICK HERE.

[Shapeshifter]

I think she was drinking Mellow Birds.

[Clau]

I don't know if it's an expression, but rest of coffee in a cup in the form of clouds means good notice from a friend!

[russmcd828]

Clouds in my coffee.  I believe it has to do with daydreaming and believing.  When you first pour milk in your coffee doesn't it look an awful lot like clouds?  I assume she was trying to help the listener associate.