The Blue Bird is a 1908 play by Belgian playwright and poet Maurice Maeterlinck. 
In the opening scene, the two children gleefully describe the beautiful decorations and rich desserts that they see in the house of a wealthy family nearby. When Bérylune says that it is wrong for the rich not to share their cakes with Tyltyl and Mytyl, the boy corrects her. It is enough that he gets to watch others’ happiness; their joy does not create envy in him. The theme is emphasized again when the children meet the Luxuries, particularly the biggest one of all, the Luxury of Being Rich. When Tyltyl turns the diamond, the hall is bathed with a dazzling brightness, and the Luxuries run wildly in search of a dark corner where they may hide their ugliness from the ethereal light. The names of such Happinesses as Innocent Thoughts and Seeing the Stars Rise and of such Joys as Being Good and Maternal Love affirm Maurice Maeterlinck’s view that true happiness lies in simple things, particularly in the warmth of family love.
At the end of the play, Tyltyl shows what he has learned about happiness.