Introvert Extrovert is an examination of the psychology of personality in with the mission of helping people better understand themselves and each other, with the ultimate goal of self actualization and personal growth. Family, relationships, friendships and the absurdity of the human condition are forefront while different personality tests such as Myers Briggs are referenced from many philosophy points of view.
Johnny and Al met because they were house mates dealing with some other especially bad house mates. The guys talk about that experience and what they now look for in a place and how introverts and extroverts can get along as house mates.