Crying For The Moon
If you are crying for the moon you are longing for what is beyond your reach.
I'm all in favor for ambition but I think when he says he'll be a millionaire by the time he's 25, he's simply crying for the moon.
crying to the moon
To swear and scream in vain, because nobody can hear you or nobody cares.
There's no chance to make him understand, I'm just crying to the moon.