I love to paint as a form of Modernism which is a philosophical movement that, along with cultural trends and changes, arose from wide-scale and far-reaching transformations in Western society during the late 19th and early 20th centuries.
That's so cool. Do you like Pablo Picasso?
Of course, he is one of my favorite sculptor and painter and to crown it all he is a Spanish  poet 
Yeah he's really cool. What makes art postmodern?
Well we can describe Postmodern as a body of art movements that sought to contradict some aspects of modernism or some aspects that emerged or developed in its aftermath.
That's cool. Who's your favorite post modern painter?
I like John Wilde for his  printmaker of fantastic imagery.
Where did post modernism start?
Postmodernism
Postmodernism is a broad movement that developed in the mid- to late 20th century across philosophy, the arts, architecture, and criticism, marking a departure from modernism. The term has been more generally applied to the historical era following modernity and the tendencies of this era. 
While encompassing a wide variety of approaches and disciplines, postmodernism is generally defined by an attitude of skepticism, irony, or rejection of the grand narratives and ideologies of modernism, often calling into question various assumptions of Enlightenment rationality. Consequently, common
Modernism
Modernism is both a philosophical movement and an art movement that, along with cultural trends and changes, arose from wide-scale and far-reaching transformations in Western society during the late 19th and early 20th centuries. Among the factors that shaped modernism were the development of modern industrial societies and the rapid growth of cities, followed then by reactions of horror to World War I. Modernism also rejected the certainty of Enlightenment thinking, and many modernists rejected religious belief.
Modernism, in general, includes the activities and creations