Pleasure is pervasive, engrossing and encompassing. At such moments one hardly remembers the moments were sad and unpleasant in life. Fun is, when one is in pain or stress , one hardly remembers the moments of pleasure and happiness. So both are encompassing and all pervasive. The scene would be entirely different when one is happy and sad at the same time. This had lead man to explore more and more about how to be happy and how to avoid pain and troubles. LbnRaj 17th May 2016.