Pie-In-The-Sky?

Hi Adams,
When an idea, promise, or something good (here the fantasy, or your dream) is unlikely to happen, or to be reached, we can call it as a pie in the sky!
Cheers,

In Germany we call that "Luftschloss". That is a "castle built out of air".

I didn't know that one! I think I'll cherish it from now on... Might even change my nickname
In French, it's a "château en Espagne"

http://www.worldwidewords.org/qa/qa-pie1.htm

This is a link to info about the term "pie in the sky" - there was a song circulated by an American socialist organization in the early 1900s that was a sarcastic response to the Salvation Army, a Christian organization that stressed that people who suffered on Earth would get their reward in Heaven. The line was "you'll have pie in the sky when you die."

(The anti-Christian sarcasm of the song is not still part of the general understanding of the phrase - now it usually means an unlikely, but much desired, future reward)

Then it's not the same as a "château en Espagne". Those castles are just fantasies of the mind, but no hint of future reward, not even of being much desired. It's mors like mythomania (but not quite).

We build castles in Spain too, but not often. Usualy we chase rainbows or cry for the moon.

What does 'chase rainbows and cry for the moon' idioms mean?

Does they mean same as 'pie in the sky': "something that you hope will happen but which is very unlikely to happen"

It's to yearn for things you'll never get.