The French idiom “être fleur bleue” translates literally to “to be a blue flower” and means to be moved emotionally, sentimental, naive, soppy and romantic. This post will explore the expression’s origine and several example sentences (with audio).
fleur bleue
to be moved emotionally

According to WordReference, a French-to-French definition of fleur bleue is “être sentimental” (to be sentimental, romantic).
Accoring to Lalanguefrancaise.com, the expression finds its origins in the German novel Henri d’Ofterdingen by Novalis from the early 19th century. The original German expression was “die blaue Blume“.
Here are some example sentences:
J’ai trop aimé ce film. J’étais si ému. J’étais fleur bleue et j’ai même pleuré.
I liked that film so much. I was so touched. I was sentimental and I even cried.
J’ai été fleur bleue quand j’ai fini le roman. Je n’ai pas arrêté de pleurer.
I was moved emotionally when I finished the novel. I couldn’t stop crying.

Fun video lesson
Video source: Maintenant tu sais
Conclustion
Congratulations! You know how to use the French expression fleur bleue. Now check our lessons covering other fun expressions avoir le cafard (to be depressed) tomber dans les pommes (to faint).