The elongated title of the book is: "Quiet: The Power of Introverts in a World That Can't Stop Talking" which I think sums it up quite well. The "Extrovert Ideal" has ruled during the last century or so and is defined by Cain as "...the omnipresent belief that the ideal self is gregarious, alpha, and comfortable in the spotlight." On the other hand, introverts have been characterized as having "second-class personality traits." Cain's book discounts the Extrovert Ideal and discusses the under looked value of the introvert to society.
I have read "Quiet" in its entirety 3 times and individual chapters when the need arises. The present world is very noisy, full of rhetoric, and divisiveness. "Quiet" grounds me and reminds me of the strengths that I have and use despite what is going on around me in order to stay balanced and grounded.