Many who build castles in the air cannot build a hut on earth.
More German Proverbs:
When the fox wants to catch geese, he wags his tail.German
Fortune give many too much, but no one enough.
German
Play not with a man till you hurt him, nor jest till you shame him.
German
One ass nicknames another "Long-ears."
German
No one betrays himself by silence.
German
They are not all friends who laugh with you.
German