想入非非的英语:have a maggot in one's head [brain]; aim [level] at the moon; allow one's fancy to run wild; aspire after the impossible; be much given to speculation; be full of whims and fancies; be in ...
想入非非的法语:s'abandonner à la rêverie;se bercer d'illusions;se perdre dans les nuages;pousser son imagination jusqu'à la divagation