How should I express Mudita or Joy for all beings? In Mudita meditation or Joy Meditation I am supposed to experience Joy for all beings. But I don't know which aspect of living beings is worth celebrating. 

My question is : How should I express Mudita or Joy for all beings?

EDIT: To support my mental dilemma I quote Maiterya.


  Just as there can be no pleasant fragrance in a cesspit There is no
  joy among the five classes of beings.
  
  – Maitreya
  
  Uttaratantra Shastra, IV, 50
The aspect that I celebrate: that despite all the difficulties, suffering, dirt, cynicism, pain etc. people still find strength to be positive, to love, to forgive, and to create beauty. Especially people who have seen difficulties are often the kindest and the most understanding of all. I think this is very beautiful.