Girls and the Blue Birds

Nowadays I am enjoying a series of these girls with blue birds.  

I was mesmerized by Maurice Maeterlinck's book 'Blue Bird' when I was little.  

Not  knowing the deep meaning of the blue bird.  

I really believed there was a blue bird and how pretty it must be.  

(I think I was somewhat frustrated I wasn't seeing any blue bird..haa haa)

What is your Blue Bird?