Perspectives are the lenses through which each of us look at everything except ourselves. Change of perspectives happen very often,sometimes in an instant.They are ephemeral.The way of thinking after a change in perspective leads to a paradigm shift. Consider comparing our paradigms with those of children:

Even the simplest of the things hold immense value to children.This kind of a perception is the most gratifying one. As we grow older,we seem to drift away from this beautiful way of life to a more barren and calculative perception. This is the reason for discontentment in an adult’s life;which is all the more ubiquitous nowadays.

A simple book which intuitively talks about Perspectives,Perceptions and Paradigm shifts is The Little Prince,by Antoine de Saint-Exupery a French  aviator.It is the most politely done mock at all of us,who do not value the simple things in life.

One of the best lines from the book would be:
It is only with the heart that one can see rightly; what is essential is invisible to the eye.